The ID issue is actually more required to get back into the USA than to get into Canada. It is on the return that you will not be admitted back into the USA unless you have photo/birth ID, which makes the passport the most practical piece of ID to use. Since most Americans don't have passports, this becomes an issue... I would certainly expect all FTers to have this essential travel document.
As for the actual procedure at Vancouver station, it seems no different from most ports of entry into the USA if you are using the bus. On such occasions one must remove bags, allow dogs to sniff them, then line up to go through a personal review of your documents...then get back onto the bus. "Welcome to the USA."
BTW, just a few steps from the RR station is Vancouver's rapid transit that will wisk you into the city nearby most major hotels for about $2.
On the way back, you'll be checked by US officials at the border. They'll come on board to check documents and select certain people for actual customs checks. Again, it is to get back into your country that the appropriate US ID is essential.