Since moving here to Vancouver from Toronto, I haven't familiarized myself with the used bookstores end much. But it would be fair to say that Vancouver has less selection of used books in different genres compared to Toronto (where toronto had dedicated bookstores on sci-fi, detective fiction before they went under...) I did work in a bookstore for almost a yr. in T.O. ...before I found my "real" jobs..
I think my book collection doesn't jive completely nor deeply with your interests...otherwise I would be happy to give away some books to you!Interested in travelogues? The closest Canadian history is on salmon fishing (hey it's important stuff where we are), biography of David Suzuki, history of Gulf Islands in artsy illustrated way, etc.
Vancouver has local chain bookstore which offers 20% discount off all their new titles --hardcover and softcover. Book Warehouse offers diverse selection.. There are 2 outlets in the downtown area....one of them not far from home.
For Canadian history, I think you will find the strongest, best selection on B.C. history of course....and aboriginal history. There are some real cool subjects in the latter area... Of course, realize that the smaller/local publishing presses would sell the books here and with discount you save money vs. special ordering from Alberta/Ontario...
This is what I look for whenever I travel in North America. when I visit a bookstore...the books published by the local /regional presses which are more difficult and maybe more expensive to order from another province/state/country.
As a long shot, send an reference question email to the Vancouver Public Library...their Central branch which the building looks like the Roman Coloseum.
I think the Goethe Institute teaches German..not sure if they have a bookstore.