Is it okay to offer to sell ROW games?

Yes, why wouldn't it be?

it would be no different than trading i'd imagine, so yea... go for it

Keep in mind that currency processing fees can be extreme. Even just going through Paypal, you can get a pretty noticeable exchange fee even with Friends & Family (which offers no protections if you get scammed, versus the standard, higher-fee seller payment approach).

So it may not end up as favorable as you expect :X

Not sure about Canada specifically, though. If it works out favorably, go for it.

hell yeah of course :D

You probably already know this, but just in case... :) I suggest limiting yourself to actual friends, at least for now... :) If you buy a Steam game for a random person in exchange for Paypal money, and next week the Paypal money disappears, that random person still has the game, and Valve won't do anything about it.

As long as you can trust the other party, you're good to go. Steam doesn't care about trading games as long as they're bought with legitimate money. Now, granted, the ToS probably forbids resale, but the practice is so widespread someone taking advantage of better regional pricing for a few friends is not going to even pop up on the radar compared to, say, greymarket resellers.