Smartphones; (Can I do this?)

Kuroi Ookami

*I changed the title since I assume most smartphones are alike and I felt claiming WP7 might make some people think they can't help me, when they can.*

(Located in Canada, buying a cellphone locks you to the Carrier who sold/leased you the phone)

So, The model I want, along with being Carrier unlocked (on eBay), has dropped considerably in price, since I guess this is what electronics do. Maybe new ones came out, I don't know. I found a number of them that are in a price range that I feel my dad may consider getting one of these for me for Christmas. *joy* Now, I have some questions, because I still don't fully understand Smartphones.

1) I don't want to go to MTS or Rogers to get a "Plan". Since I am not buying/leasing a phone through them and going on a 3-5 year contract, they feel that is reason enough to charge, what I feel, are outrageous prices. I'm trying to replace my home phone with a cellphone, not feel like I'm paying my home phone bill 2 or 3 times over every month. So, can I use Pay As You Go Minutes cards on a Smartphone? If yes, Does this provide me with a phone number to give to people, or can I only call out?

2) Again, I don't want to get a Data Plan for the same reason as above. The amount of time I'd need to use wifi outside of my home or a friend's place is very minimal. Without activating the phone to a Carrier can I just use my/a friend's home wireless network for my phone's wifi?

I'm not really sure what else to ask.

So basically, can I use a Smartphone with the whole pay as you go card stuff, and can I use my own wifi without having a Carrier providing me with a Data plan to fall back onto? Will the phone just outright not work if a Carrier doesn't activate it for me? If that's the case, I'd have to start narrowing down the lesser of evils to see if it's still worth it.

Thanks for helping me with my lack of understanding, and trying to help me to understand!