"Solve the issue of plots taken up by inactive players. Have plot be freed after X time after sub runs out for example. (This one is even good business for you)"
They already do this. 45 days.

For the most part I agree. However, I'm not sure I agree with FCs getting so much preferential treatment. Give them some, as one house benefiting many is better than benefiting only 1 or 2. Though, i've been waiting for a hosue for over a year and a half with money kept aside for it, and there are more FCs than you think. I'd hate to be locked out because I have to be FC to get a house, resulting in all the houses being taken by an FC and I end up with no house again. Either way, people will just make FCs with only themselves in just get around that.