Great stuff Frogboy!
I like the idea of AI demigods that replace dropped players not providing gold/XP.
Any opinions on that?
They can maybe give 1/4 exp and gold. I don't know if 0 is completely fair. Part of the problem is they need to be a bit more careful about getting killed. I have seen some of the AI gods be totally reckless and thereby feed the enemy.
Adding to your options list:
* If you are going to have mods choosable like game options, look into allowing auto-distribution of the mod via the game client to people who join the game. The biggest barrier to people playing with Mods is making sure everyone is using the same version of the Mod, or getting the mod out to people who don't normally install such things. Auto-Distribution is critical if you want to make a Mod friendly gaming community.
* It would be nice to see player skill level via the matchmaking client. The biggest frustration I find is that there are a lot of pre-made teams of very skilled players constantly fighting people who are still learning the game. By seeing an indicator for skill level / wins / rank, etc. people can make informed choices and try and find games that should be more fun for both teams.