If you are committed to staying in and immediately around the city of Vancouver, you have a number of locations for sunrise/sunset photography. Rather than trying to base yourself in the downtown core, I would suggest you consider the Capilano Road motel strip. Motels are reasonable in quality. It is located immediately over the Lions Gate Bridge from the core of Vancouver, is about a five/ten minute drive from the core (on a good day, traffic dependent) over the bridge and through the Stanley Park causeway. For family excursions, you are close to Stanley park, with ocean beaches, kids play areas/water park, Vancouver aquarium etc, two minutes from the Park Royal mall and Ambleside Beach area, 5 minutes from Capilano canyon swinging bridge and the Grouse Mountain tram and a whole host of other family oriented stuff. For photography, you would be a few minute drive to Stanley Park where you can capture sunrise shots of the city of Vancouver, Lions Gate Bridge, beaches and harbour as well as 10/15 minutes from the north shore mountains and scenic viewpoints of the city and harbour (as a bonus, you're also a few minutes from one of the best camera stores in the downtown area).
If, however, you wish to be outside of the city area and in the general greater Vancouver area, Harrison Hotsprings is a couple hour drive from Vancouver, is on a lake, with a beach, public pool, hotel/motel, restaurants and a few small galleries/craft stores. From there, you have the option of a number of photography and family excursions. This area is quite popular with families.
As noted in a previous post, the Vancouver area has numerous photography locations and I could go on for quite a bit with info. If you wish, I can provide explicit detail by e-mail as well as answer any other questions you may have.
Marv