The exhaust can be fixe with Rolt's adjustable scripts, as I said above. The engines, I don't know about LE, cause I have never used it, or encountered that problem, but I have all the engines you stated installed on STAGE1 with LE2MWM mod installed with no problems, so I'd recommend that over LE any day.
LINK FOR STAGE1 - STAGE1, 2.2.1 MWM with some mods, the most stable version.
LINK FOR LE2MWM- LE2MWM, a mod that allows LE mods on MWM.