I know you can't use the native email client, but I plan to use the GMail app anyways. (I switch between phones so I don't want the BB plan; just my total internet plan).

Besides the native email app, does anything else not work? Can I use App World?

Thanks

Nothing is guaranteed to work if you don't have the BlackBerry data plan.

That said, why not switch? The BlackBerry data plan works in other phones. It has un-proxied access just like Total Internet.

You won't be able to get push email, use BB Messenger, BB Browser, App World, etc. Check these links out:
What do I need a Data Plan for? - BlackBerryFAQ

How to use BlackBerry on Generic Data Plan - BlackBerryFAQ