I don't monitor my number of fans. I just think they will increase on winning game and there is no event to reduce it.
My teams promote in every season. So I don't know if ticket price can be increased in those seasons that teams stayed in same levels. I even just notice that ticket prices of different competitions can largely vary while full attendance can still be kept.
As I remember, at low levels, even increase ticket price by 1 is a large increase in terms of percentage. So changes in ticket prices is less frequent.
I also increase ticket price by 1 if my stadium is full in home court match. If stadium is not full after ticket price increase, I will resume old ticket price. This simple strategy works for my teams in the past. I just started to record ticket prices and attendance in last 2 seasons, and now notice that the attendance is actually more sensitive to match results than I thought. I have been stupid on this. But I actually think this makes the game more interesting.