-Local, easy to use game hosting that can accomodate let's say up to 10 players.
It's possible. 8 players are possible at least.
-The ability to play among friends as a godlike dungeon master that can spawn monsters, possess NPCs, play invisibly, and just generally tell stories with the powers needed to do so.
Everything you mention is possible but will require some really heavy scripting work. There is no build-in DM tools but you can create them with some advanced scripting.
-Persistant player character save files on the hosting machine, bonus points if there's a way for a DM to edit them for things like player name changes.
All information is stored on host PC. Savefiles are kinda editable.
