With a few exceptions, it's impossible to beat Jardines / CKH. They own half the property so as soon as you create a disruptive idea they are gonna just build a competitor without the burden of rent. This especially true of the O2O component of your business. This is why most companies form strategic partnerships with one of the conglomerates when they want to enter HK.
HKTVMall is a notable exception but the company has access to a lot of capital.
For e-commerce it's usually best to do the warehousing in a cheaper jurisdiction outside of HK and form a partnership with one of the major couriers (most likely SF express).