Sometimes being obsessive can be good, in a weird sort of way. I think of it more as "determined." Or a maniacal refusal to give up. 
Some progress! No thanks to the documentation or support pages... There was a vague reference in a support document about omitting an Access "autonumber" field, and a non-specific reference in another statement about using the "sync only mapped fields" option. Well, if you dig and experiment enough, and decide to manually remap EVERY SINGLE FIELD, the default autonumber field can be omitted from the sync.
A test record has now synced a change in each direction, which is a MAJOR accomplishment. My frustration with this is that the online support page steps through setting up a new sync between an Access table and HB. And it specifically says NOT to use the mapped fields option! Now, given that Access has, by default, an unsyncable autonumber field, what does that mean? It means that no Access database will ever sync when set up per the instructions in the documentation and the support pages. And in my case, it means I have well over two full working days of MY time invested in figuring it out, in spite of DDH's worse-than-useless (wrong info is always worse than no info) documentation and support pages. 
It does appear to work now, although I'll be skeptical until I have more history and reliability. And while it's about the only thing available to sync with Access on WM, I honestly can't recommend it. It's a dog on its own, and worse compared to SLTG for Palm OS.
Why there are such glaring, gaping holes in using M$ stuff with M$ stuff is beyond me. I had less problems using WinME for 7 years than I've had using M$ documents on WM.
At any rate, I've had at least some success, but considering the overall cost it's a hollow victory. As far as I'm concerned, DDH should have been paying me to set this crap up. A nap would have been a better use of my time. If I weren't such a stubborn SOB...
