John,
I endorse your use of a GAL. I have been using them for many years and what they save in board space and what they simplify in terms of timing analysis and synthesis more than offset the limitation for some that do not have the ability to program them. There are always way to get them programmed. I will join you in providing free programming services for N8VEM supporters. Send me the GAL and as long as I have the ,JED file I'll help.
I think you have already captured my recommendations especially those regarding what were U18 & U19 and the pull ups.
As far as the 82C55 goes I agree that an alternative might be better but keeping the code base stable is a higher priority. As I have noted my V2a board is using the Toshiba 10 MHz device with not a single hiccup.
So put me on the waiting list for two (2) boards.
Thanks,
Rich Leary