A) Click on "Edit Forums" in your admin centre, and choose "Edit Settings" from the pull-down menu next to the forum you want to remove their name from (I'm assuming they're already modded on all forums here). Just remove their name from the "Mod Display String" box. It doesn't affect their mod powers, just how they're displayed.
B) "Edit Users" in your admin centre, put a check in the boxes of people to giv mod positions; Choose "Assign Mods", and then check all of the forums, and the powers that you wish to give them

C) Good idea, I like ulletin's way of doing this. Have to put that on the to-do list.

But for now, you could just click "Edit Template" in your admin centre, and add their e-mails in the header or footer. Then everybody can see them.

Or add them to your "Welcome Page" and link to that from your template.
D) Good thought - in fact, it's really an easy addition, so I'll add it now. Give me 10 mintues, then look for "Disable User Delete" in the board settings...