First off, welcome to Hong Kong! Similar to myself, when one first arrives in Hong Kong, one must really put aside one's previous ideas about "space" in a home. It can be quite disconcerting coming over from suburbia America, for example, and first experiencing the living space of Hong Kong. Myself, I was absolutely culture shocked when I first arrived here many years ago, though after some time, one finds there are certain benefits of living in Hong Kong that overcomes the tight space and can make it perhaps in certain instances even more enjoyable than living in a typical house overseas.
However, the irony of your experiences so far is that you have seen actually what would be considered in Hong Kong as very vast and desirable living spaces. In general, to have any garden of any sort is already considered an incredible "luxury". Most Hong Kong apartments don't even have a small balcony, not to mention a "garden". As for a "narrow staircase", that is almost an oxymoron in Hong Kong as 99% of the units here won't have anything close to a staircase, where a few steps between the dining room and living room is already considered a rare luxury. And almost any kitchen in Hong Kong would be considered "small" when compared to kitchens in the US, for example. Surely, I've never seen a kitchen in Hong Kong that would compare to one in my old house in the US, which was probably at least 600 sq. ft with a large island in the center, even the units I've looked at on The Peak such as Severn 8, which cost 10 times what my house in the US was worth.
I trust you haven't viewed the typical flats in Hong Kong which are perhaps 700 square feet, and even with your budget, might extend toward 1,000-1,250 square feet in a flat close to Central. Now THAT would be a culture shock!
Of course, since you will be working in Shatin, your options for affordable housing should be much greater, particularly if you stay in Shatin.
But as you are looking at Tai Po as well, the options you've seen are actually excellent. One thing I do want to advise is that if you think your budget will remain around $35K in the upcoming years, it's probably best not to rent at The Beverly Hills.
The reason for this is because most of the units at The Beverly Hills were sold at the end of 2007 and the beginning of last year, at the property market's recent peak, right before the severe market correction. Prior to the correction, the market was rising at an incredible fast pace for years, and thus there was a trend of speculation in the local property market and especially at The Beverly Hills, in which there were many buyers that bought several units all at the same time, hoping to "flip" them before the year was out. As with most new Hong Kong developments, developers generally give new first-hand buyers an option of up to a year to "close" on the deal, and therefore speculators only needed to put in 15% of the total value of the house, and have a whole year to try to sell it before closing with the developer and then having to pay for the house in full or more likely, get a mortgage with the bank.
With the property market correction happening right after most of these units were sold, many of these speculators were forced to either sell these units at a high loss (if they were desperate) or have to get a mortgage for the house and release it for rental for the time being to only partially cover their mortgage before the market picks up and they can sell it for either what they paid for it or ideally, at a profit.
Where I'm going with this is because of the market conditions, units at The Beverly Hills have been leasing at severely depressed prices, and only because the owners needed some sort of cashflow to pay off the mortgage. However, generally, for what owners paid for their units prior to the correction, a typical mortgage for a Beverly Hills unit bought first-hand would be $55K+ plus if it was a 70% loan over 30 years, which is reflective of what the lease would be in a healthy market.
Keep in mind that it is a truism in Hong Kong to never buy a brand-new property with leasing it out in mind if you cannot withstand a loss for the first few years. That is because generally with any new property development in Hong Kong, there is such an initial flood of inventory into the leasing market that the prices will be low initially, and will rise gradually over the next couple of years once inventory has been reduced. This factor combined with the market correction has resulted in the current low leasing prices at The Beverly Hills.
Therefore, with the market seemingly picking up gradually, the current low leases will surely increase and no doubt any landlord will increase their rents to as much as the market will bear as soon as possible, and with a typical leasing contract, that would be in 14 months. It's a similar case with SARS a few years ago when rentals became so low, but quickly rebounded within a year or two so that many renters were forced to move out of their apartment when their $30K SARS lease all of a sudden turned into $45K or $50K. This is not an exaggeration, these things really happened and so as it is, welcome to the Hong Kong property market.
In my view, for the same rental, Casa Marina would be a better bet, as it is a much older development than The Beverly Hills, over 10 years old I believe which has allowed it's inventory to remain steady and low, and is developed by the same developer. The leases of Casa Marina, not to mention the sale prices, have always been relatively lower, and in actuality, have not dropped as much in the recent correction. Therefore, it's a good bet that the leases at Casa Marina will not rise much more than they are currently, even if the property market picks up. Thus, there is less of a chance that you will need to leave the unit after a year or have to pay a much higher lease in the immediate future.
Besides this, you also have to consider that The Beverly Hills was developed mostly for owners in mind, and not so much renters. This explains why "conveniences" of generally less-affordable housing such as shuttle buses and convenience stores are missing. They are generally not needed as most residents, and the vast majority of residents in The Beverly Hills are owners of their property, have at least one or two cars and their own drivers.
There really isn't a point living in a place like The Beverly Hills without your own car and better yet, with your own driver. To do so would be incredibly inconvenient, and the benefits of living in a somewhat distant gated community such as The Beverly Hills would be overshadowed by the inconvenience of trying to use public transportation, especially when grocery shopping and the like. Just having your own car really isn't enough as parking can be nightmare in Hong Kong, and also very expensive, and in that case, often it's better to just take taxis, for example, if you are living in the city. Having a driver allows you all the benefits of a taxi, but just in a much nicer ride, and you can be dropped off and picked up at the door without worrying about carrying your groceries to the parking structure, for example, which in most instances can be far away, especially when you're carrying five bags of groceries.
Also, the reason why a development like The Beverly Hills is much more attractive to owners than renters is because generally the units need a bit of remodeling to really get the most of out the units. For example, you mentioned the stairs and whether it would be safe for your 3 year-old daughter. Without installing full carpeting on the stairs, which are a very hard tile, and also sturdy, permanent child safety gates on each level, it really would be quite dangerous for a young child. With the staircases in a U shape, a child could easily roll down a couple of flights of stairs causing massive injuries without the extra grip and insulation of a thick rug and having the safety gates to prevent the accident in the first place.
Besides this, certain features of the units such as the roof terraces and large balconies extending from the living room (if the unit has one) is only really good if you add outdoor deck flooring and ideally, some custom-sized outdoor furniture and perhaps a hot tub on the roof, which many Beverly Hills owners have. Otherwise, the space is pretty much wasted.
In The Beverly Hills, I believe there is also an unused space next to the garage in the basement that many owners turn into an additional bedroom including bathroom, usually for the driver or helpers. This space can be accessed by knocking down a dry wall, and it's supposedly a relatively large space with 20 ft. ceilings as it was designed to house the air-conditioning units. The AC units are then moved up higher and a false ceiling is added. By converting this space, owners gain an additional 100+ square feet and an extra room for the help.
Of course, you can add these furnishings as a renter, granted with permission from the owner, but most people would feel it as a total waste to renovate a unit that you do not own. There is probably little point in sinking a couple of million into renovations if you don't own the unit, and doing so defeats the purpose of renting anyway.
Overall, the seemingly low leasing rates at the moment of a property like The Beverly Hills is fairly deceiving in terms of what it actually costs to live there. With the additional costs of buying a car, hiring a driver, gas, toll fees, parking (all of which are astronomical in Hong Kong), and extra helpers to help maintain the house, the overall expenditure is much, much higher than living in a more modest house or apartment with greater convenience, such as having shuttle buses, public transportation, and having everyday shopping such as convenience and grocery stores nearby. And with the leasing prices bound to jump dramatically once the property market recovers, many of whom say within the next 6 months, you could find yourself either having to move to another property that you can afford or pay a much higher price in lease so to stay in a unit that you've grown attached to.