Hmm, using hg for Windows last summer, it never failed to do exactly the opposite of what I described. Perhaps its just a Windows thing, or the version of Mercurial I was using.
Yes, because Windows doesn't have less. It does whatever makes sense on each platform -- so on Windows it'll also use notepad for commit messages by default, and look for both .hgrc and Mercurial.ini in the home directory.
The pager and editor are configurable, of course. I have it set up to use emacsclient on Windows.
