ClockworkMod Recovery allows you to flash ROMs directly from your EVO without having to be connected to your PC. Toast's custom recovery requires that you be connected to your PC and use adb, but it is the only way to write to /system. However, you shouldn't need to write to /system unless there is something very specific that you want to do since most custom ROMs are already optimized. In order to get the donate version of Titanium Backup, you must donate a few bucks to the dev, and he will send you a license key that activates all of the donate features. The full instructions are in the app once you download it. Fresh ROM puts the apps in a separate folder on the SD card. They aren't installed, so Titanium Backup won't touch them. You can use a file explorer like EStrong or ASTRO to individually restore any features that you would like.