Google Maps:
Use the link below and install the cab file from the browser in your phone. Its works perfect for me.
http://www.ppcgeeks.com/2009/12/02/google-maps-for-windows-mobile-updated-to-v3-3/
I have done most of the same mods as laymanspc and all have worked for me as well. One other that I would like to add however is adding in support for Widgets. For some reason it was pulled from the USC build of WM 6.5 (according to HTC). You can add this support back in by using the attached cab's. (I don't have the links to the threads that I got these from at the moment so I apologize to the developers of these fixes for not giving them their due).
What sort of Widgets are available?
Just an FYI also, I found a Theme called Dark that worked pretty well.
http://forum.ppcgeeks.com/showthread.php?t=96575
I dont have it installed anymore because of some other issue i was having but from what i remember everything worked.
Sweet thread btw. I cant tell you how much time i have spent looking for stuff that works on the USCC HTC TP2.
What is the Mighty Rom?