I agree with most of the things in the OP, the only thing that I need convincing is the addons part. I think allowing addons can ruin a game experience and is not always a good thing. If you allow addons to be created and used by the mass, then some addons will become mandatory for game-play and will be looked over when seeking a group if you don't have this or that addon to make the game even more easier than it is now.

I'll say no to addons for now.