So, perhaps better covered in a different thread, are there any other
suggestions for client bridge replacement candidates - ones which would
allow me to click my bookmark/favorite/whatever to reach the
configuration page, and point and click on the desired connection point
- but also *not* connect to any until asked, regardless of strength??

You've been told this info before, several times. You're trying to use gear
that plainly does not do what you want. Stop trying. Use gear that's known
to do what you're after.

It's trivial, get a pair of WRT54G routers, use one as a link to the shore.
Use the other as a on-boat access point, wired to the first one. Done.
Then it's just a trivial matter to browse to the shore linking device,
picking the on-shore SSID desired and you're done.