The bloatware trick saves you quite a bit of Ram. Most of the stuff can be reinstalled via cabs if you need it. XDA has the cabs posted in one of their threads (
xda-developers - Xda-developers).
Yes you would lose EVERYTHING you have installed. The bloatware trick is a Hard reset. So it brings your tilt to ground zero. It is POSSIBLE that if you did a selective backup with the included sprite backup software, you could save your programs, but it would probably have everything (including what you are removing with the remove bloatware trick.
Don't know about the MS Streets. I use google maps.
1 other thing that should be mentioned. IF you hard reset, after you have reloaded your MUST HAVE software, and sync'd your contacts/tasks/calendar, Perform a backup using sprite. Keep a copy of that backup on your storage card, and a copy on your desktop. This can save time if you need to reset again.
hth.