Hi;
If you are still looking for a foot care provider in Vancouver I hope it is ok that I recommend my Wife.
She is a podologist and specializes in foot care such as what you have described for your calluses and corns; complete foot overhauls. You can find out more about her service at:
www.medipedi.ca
She is in the Downtown Wellness Centre 1200 Burrard Street 605 and there is one of Vancouvers Top Chiropractor's who would be able to help you with Orthotics and Gait if needed.
All the Best.