OK I'm back to old habits -- having re-discovered old habits weren't completely stupid.
Leor Zolman's BDS C compiler it is. It's got a lot of language cheats and shortcomings, but it's all scaled appropriately for small machines.
It's binary output is HALF the size of Aztec C's, which is fairly compliant (to a very old standard). I need code, not compliance.
WordStar has many shortcomings, I could not remember how minimal it is, but it is rock solid and that matters.
I'd like to find a copy of PMATE for CP/M (plenty around for DOS)
Leor seems like a great guy.