some of my friends got stuck in edmonton for more than a day..
if you go south to Calgery check the bussystem towards the airport. dont know the place too well but the airport is already far out of the city.
or check: http://hitchwiki.org/en/Edmonton
however i would go over Jasper if you want to avoid big cities. that route should be fine for hitchhiking.
Kamloops is a really spread out city so try to catch a ride to the other side or you end up walking lots.
a good spot is the travel centre (massive gasstation/truckstop) a little south of the city about 2 or 3 km before the junction transcanadian highway / Coquihalla
the transcanadian is beautifull but can be slow sometimes with longer waitingtimes