PRE SALES QUESTION: Per Item 88 below, PM can’t automatically notify members of new posts. But is there a possible workaround? Can members be emailed periodically through a mail list (automatically; say, weekly?) with a link to the site?

Joe Lapp wrote a Simple Digest Module that will help with what you want.

Thanks. One more question: If PM can’t automatically notify members of new posts, and this forum is just a slick use of PM, how then can members be notified via email of new posts on threads of this forum??!!

These forums are run by pMachine Pro (I think), not EE.

There is also a difference between notification of new comments in a thread/entry to which you subscribed and being notified of completely new entries in the weblog/forum.  Both pMachine and EE have the ability to allow a user to be notified of additional comments when they post a comment in a thread/entry.