Your itinerary sounds reasonable, especially since you will be leaving the top tourist spots (Capilano/Grouse) to a Monday. Kids are still in school in mid-December so the crowds won't be too bad on a weekday.

Are you taking Helijet from Victoria to Vancouver? If so, you will arrive right downtown near Canada Place/Gastown where you will be within walking distance to decent hotels and restaurants. As long as your hotel is in the downtown area, you should have no problem getting around. When its time to take Amtrak south, it's really just outside of the downtown core, and accessible by public transit.