I understand you may not want S-Off, not sure why
. But if it's a warrenty thing, you already voided that if you used the HTC Unlock Tool. Also a few other things that were mentioned in the above posts are very important. One is that most of the Roms, not all. But most do have a custom kernel. As mentioned above, that will cause Errors when it tries to flash and cannot. The other is that to have WiFi, and USB Tether. It will be easier to accomplish if your fully rooted. The people here are just trying to save you headaches later on.
MikROMs Since 3/13/11