Here's an update: I went to DBS, Hang Seng and Citibank today.

Unfortunately the staff I spoke to seemed not very knowledgable about their different accounts and rules, and they had to consult various manuals a lot, and seemed very uncertain about almost everything I asked about.

Citibank:
- There are transfer out and transfer in limits for international wires. The staff did not specify the limits.
- The staff told me larger amounts (what a large amount constitutes was not clarified) will be subject to investigation, and I will need to provide evidence of what those funds are/why they are being sent to my account. She did not say whether they will freeze the funds pending completion of their investigation into the funds. Opening a Citibank account for international wire transfers seems like begging for trouble. So this bank is out of the question.


DBS:
- The staff I talked to were probably a fresh grads and didn't have much of a clue, so some of this info I got from their website
- No limits whatsoever on inbound/outbound transfers.
- Online banking and account services explicitly geared towards international wires
- Apparently outbound wire transfers are HK$400 - seems very high, not sure if accurate. Anyone knows how much? Their website only seems to show a promotion fee at the moment, and not the regular fee. Inbound fee is $65.
- Lowest account balance permitted is HK$200,000. There is no way of opening an account without depositing HK$200,000 immediately. There are no account options with a lower balance requirement. This is their "base" option. It includes savings, checking and multi-currency in one package.
- Aside from the more expensive wires (if that really is the price) and the higher minimum balance, they seem good "on paper"

Hang Seng:
- No intention of using them but stopped by just to see
- Staff told me there are no limitations on wire transfers and that wires originating overseas are considered "deposits" (i.e. they are not considered gain/income/profits in any way, just funds added to your accounts). He made it sound like they were extremely lenient when it comes to these kinds of things.

Then on the way out I met a former acquaintance who works there. We chatted for a while and I also took the opportunity to ask him about my situation.

He recommended me to not join any of the international banks with presence in many countries as they tend to be far more stringent in terms of following regulations even more strictly than they have to. They would me more likely to look into wires going in and out of HK. He suggested me to join Bank of China. He said they are more relaxed than banks like Citi, HSBC, Standard Chartered, DBS (due to the area BoC serve). He also questioned what I told him the Hang Seng counter staff told me about wires in and out of Hang Seng. He said such activity might be reviewed, and while he didn't think it would cause any problem, it would largely be up to the reviewer.

I also discussed my investment activities with him and he said that in his opinion it would not be considered a commercial activity. But a reviewer might have their own interpretation...

So if HSBC and Standard Chartered have already been excluded, and Citibank turns out to not be suitable as well, then on paper just in terms of the intended activity and functionality I think DBS seem most promising. But the $400 outbound wire fee, if accurate, is very high. And the $200,000 minimum also seem a bit high for the most basic account, though I'm wondering whether such a minimum, would make them less suspicious about "larger" activity of funds being transferred in an out (as the account seems geared towards such international transfer activity).

I did not have a chance to visit Bank of China before they closed, so not sure how they compare yet.