I agree with points #4, #6 and #7 the most.
On #4, I don't necessarily think it's a must to have more than 9 slots to manage your empire, but it would both improve quality of life and give more gameplay depth. Also, having to exile knights is especially annoying -- as in not a "game enhancing" feature.
On #6, a 90% debuff is just completely off.
Starting point should be higher
A mechanism whereby specialized buildings improve town output would be an option
Another option would be to hire a "Governor" with no special bonuses (unlike knights) but who can manage the town in a vanilla way
Some traditions should improve these scores, for example something around "centralization of power/authority"
On #7, the audience trade options are a bit limited at the moment. The negotiation part of the game needs more depth, if only with counter offers as an example and priority.