Second...My understanding is that this is correct. If you have twrp you should be able to flash a rooted ROM and therefore gain root
Sent using my LTEVO
As long as the ROM has the proper su binaries and apk, you should have root access in it. The root that happens in regawMOD is to gain local root in the stock OS though, which is needed for titanium backup if you wanted to carry you're app data over to the new ROM (or if you just want to be rooted and stick with stock).
Sent from my EVO LTE