BMW Repair: 84 318i starter / Idle Surge, hex bolts, vacuum leaks

Question
Hello,
I have two questions:  First I'm trying to change out my own starter and I have every single bolt removed EXCEPT the main bracket that holds the entire starter in it's attached position.  It looks like a capital "A" bent in a 90 degree angle where the lower legs of the "A" are flush with the tail end of the starter and secured with two small nuts.  The top point of the "A" is flush with the engine body and held with the bane of my existence.  An odd, hex shaped bolt that bolts the "A" bracket to the engine.  I picked up 2 sets of hex wrenches, one metric and one standard (Just in case) and for the life of me, with liquid wrench, WD-40 and all the strength I can muster, I can't move this bolt in either direction.  Do hex bolts turn the same as regular ones?  Or is the righty-tighty lefty-loosy backwards on this particular nut?

The second question is: awhile ago, the engine just started surging once started up to around 3000 RPMs on its own.  It's not an odd "warm-up" fluctuation as the car continues to sit at 3000 RPMs, but once a minute or so, dips down to 700 and right back up to 3000.  It won't quit after "warm-up" and just continues to do it constantly.  I have no vacuum leaks and the fuel system seems fine.  I think it's Motronic.  Any help whatsoever would be very greatly appreciated.

Answer
In regard to the starter, I am not 100% sure as I have not worked on any vehicles before 1990 model year. I will give you a suggestion. Wrenches do not provide much leverage, sometimes in order to loosen stubborn bolts, you need more leverage. You can gain more leverage by using a longer wrench or a longer ratchet. You will only need metric sizes to do repairs on a BMW. As for the idle surge, the car may have an idle valve that controls the idle speed. Sometimes they stick and cause engine stalling or erratic idle.