The things we'd see if this game had a modding community like...

[LiadansWhisper]

Only thing I worry about is if the game becomes too depended on battle mods. IE: When Lucifron turned into mashing the Decursive button to dispel his mass curse. Things like casting/using spells/abilities should not be given access (which Blizz deprecated in the TBC update).

Blizz broke the crap out of mods that do that. There was the issue with that one mod that drew "in-world" during ICC in Wrath of the Lich King, but they broke that one, too (it really needed breaking...it just trivialized encounters -_-). That said, the ability to re-skin my UI, control what buffs and debuffs show on my party frames, and resize them...would be amazing.

[Magis]

Blizz broke the crap out of mods that do that. There was the issue with that one mod that drew "in-world" during ICC in Wrath of the Lich King, but they broke that one, too (it really needed breaking...it just trivialized encounters -_-). That said, the ability to re-skin my UI, control what buffs and debuffs show on my party frames, and resize them...would be amazing.

Indeed, strictly UI stuff is where these addons shine. Another idea I was thinking which Erana reminded me of is a soundtrack mod. Customized every zone to play it's own custom music. I myself would probably replace it with a mix of XIV/XI music.

This of course depends on how much freedom SE gives us coders.

Oh yea, and a tool that actually tries to block gil spammers.