AFAIK, any iPhone will work on Telus, however if it is locked to another provider yyou will need to get it unlocked first. This process I am not 100% sure about, but I think some jailbreaks will allow you to unlock as well.
To your other question, Telus seems to support Data sharing.
http://www.telusmobility.com/en/AB/tablets/data.shtml