I would recommend trying to go to Pamela Youde in the Eastern district (Chai Wan), or getting a private room at QMH if your insurance will cover it. If you're in a private room, the visiting hours are relaxed AND older children are allowed in. If you are in the ward (in any public hospital), there are only 3 hrs of visiting per day, and children are pretty strictly not allowed in. The reason why I suggest Pamela Youde is that they have a "special accommodation ward" which is a 4 bed room which has 12 hrs of visiting a day and allows children - but it only costs ~$7000 (as opposed to ~$100,000 for fully private).
I've had two babies at QMH and it has its pros and cons - but I would definitely choose Pamela Youde over QM if possible. Technically, you should go to the hospital that is your district hospital. QM is the half of Hong Kong island west of Causeway Bay, and PY is from around Tin Hau and east.
With my 2nd daughter, she was in NICU and I knew I'd be leaving home without her, so they allowed me early discharge around 15 hours after she was born. But that was for just me, not the baby. I've heard of some people getting early discharge after the first day, but I've also had friends who they rejected it for various reasons. I wouldn't count on getting early discharge, but you could always ask.
When you are in labour, hubby can only be with you in the delivery room. You only go to delivery after you are 3cm dilated, so if you are progressing slowly, you may be admitted to the hospital but not to delivery - in which case, you could either a) leave the ward and walk around the hospital grounds, or b) stay in the ward, and your hubby is only allowed in for those specific 3 hours. If you labour at home and get to the hospital after you are 3cm dilated, you will be with your husband for the rest of the labour/delivery. EXCEPT if it's an emergency C-section.