With regard to blocking bot accounts...

Well, http://bugzilla.wikimedia.org/show_bug.cgi?id=1294 is what I'm wishing for. And as it happens, http://bugzilla.wikimedia.org/show_bug.cgi?id=550 seems to have consensus on en that it should be implemented.

In the meantime, account-blocking has been working fine to keep good-faith bots from going out of control, so there's no need to fret about lacking full-featured blocks.

With regard to notes on bot talk pages...

Ah, I had forgotten about the "You have new messages..." banner. That would actually be a rather clever feature to add. My bot Pearle doesn't check for that now; I just have to check her talk page frequently myself.

Some bot operators redirect their bot's talk page to their own talk page, just to make things easier for themselves. That complicates making such a nifty feature a *requirement*. I think I'll add it to WP:B as a suggestion, though.

-B.