I think you've already changed your account to the correct settings, but just to make sure everything is superduper clear:
All you need is the 5.99 tzones (or whatever they call it, just make sure its 5.99). It gives you access to unlimited edge data, but with a few ports blocked.
The other plan (29.99) gives you same speed/access, but with no ports blocked and free access at any tmobile sponsored wifi hotspots (i.e. starbucks, barnes and nobles, etc) This completely unessecary for you as you dont have a wifi capable phone.
I for one cant use any IM*programs, but it may just be cause they're expired. I would give them a try anyways, as recently, tmobile has opened some previously closed ports in tzones.
also, with the proxy ip in your laptop browser, you can teather. that is something that has recently been allowed, but still, you will need to set up a proxy exception in your browser.
And just to clear this up... Symtorrent works perfectlly with 5.99 plan. I use it all the time, and consistently get around 20KB a second down, depending on torrent health and signal strength.
Thats it, hope this helps, and welcome to all you can eat edge with a kickass symbian phone.
Im writing this from my N70, at University of Houston, while eating lunch outside, using my bluetooth keyboard.
Life is good!
Regards,
-Phono