A number of the things you've listed aren't actually possible using the Lua programming language. Some of the others are, it all depends on the amount of leeway Zenimax gives us.
My hope is that they will continue to let us have a robust API and that they will do like other companies have done - judiciously lock down certain very specific parts of the API if and when it becomes necessary.
I would also like to see them give us an "AddOn Policy" of some form. Give us a list of the things that they categorically do not want us doing. It's a lot easier to police things when there is a clear statement of what isn't acceptable.
Honestly, if I were to say what I really wished, it would be that people not create/use things that they bloody well know ZOS won't like in the first place. But I also know damn well after all these years that there are going to be some folks out there that will push beyond the 'acceptable' limit and, in the process, spoil it for the rest of us.*
[edit]* And that's the point at which the community (users, addon devs, ESOUI, etc.) should be going "hey, not cool, I'm not going to use/write/host that". One thing the OP and others new to our sites will discover, and hopefully be reassured by, is that we have some pretty firm guidelines of our own and our standards are very high. As others that have known us and used our sites for years can also attest to is that we have great communities. When something is just not copacetic, folks make it known and it gets dealt with.