I had a 95 Tsi, bought new and drove the crap out of it.... fun when you keep the turbo spooled up, but pretty heavy around town. I always had problems with windshield fogging like crazy in the winter.
you're going to have to retain power steering probably.... so plan on an electric pump for that.
EV build wise..... an 11" motor will be a screamer, and w/ awd you might keep it on the road.
I would suggest NOT 'phasing' in more batteries for higher voltage later. You really don't want to deal with different ages of cells potentially from different batches, changing your charger, dc-dc, etc. Also, a word of caution in going over 160v nominal is that components get a lot harder to find and much more expensive. To keep weight and cost down, I'd stick w/ 156v nominal x 100ah 'new' CALBs unless you REALLY need more range. You're going to run out of room pretty quick since the drive train limits where you can hang battery boxes, unless you give up the micro rear seat/cargo area completely.....
oh, just checked your blog.... was wondering if you would have room for an 11". you might be better to switch to twin 9" ?! If are still considering an offset, ReBirth has done some pretty wild twin adaptors that are offset.