Well, besides all the active / passive stuff - the supporter / non-supporter thing is pretty different from what you´re coming from.
Being a supporter doesn´t make you a more active player than any other, aswell as being a GM doesn´t switch you from being a user towards an "owner".
The transfer fee is actually something to stabilize rosters, which is a highly recommended feature by both supporters and non-supporters. There´s a huge dissatisfaction with teams constantly changing their rosters not only because of "the benefits" for those who do, but also because it´s a annoying thing to cover with.
It´s fine that you gain -some- advantages by being active and around all the time, but it´s silly that you -have- to be around 24/7 to get to the top. By removing all fiscal limitations to day-trading and probably even going the next steps you´d effectively punish those who spend medium time with the game, which is probably 60% of the users. being around often enough to keep the team and franchise intact, but not logging in at least 2-3 times a day is a perfectly fine concept to keep the game interesting for a large community. if you lose contact "to the rest of the league" because you have to cut down your online activity even for just two or three weeks, you´ll be quickly off this site, as it happens to pretty much everybody at some point. If you make any MMO a game where 24/7 is key, you´ll shrink it down to a core of probably addicted and high octane players. You need to find a balance between "some" benefits and "still playable" for those medium users.
The fiscal limitations stabilize the game in a way, as they make it harder to "print money" out of transfer list steals. they also keep the economy balanced to some degree, and they encourage people to develop or at least plan their teams personal resources.
In the end, this might not be the most realistic transfer list simulation nor the greatest economic simulations of all times, but any professional sports team day-trading 2-3 times their usual roster size over the course of a season for no financial share going anywhere would be so much out of line that it´s not even worth mentioning. Even in real life there´s -always- someone who grabs a part of the stick, so why shouldn´t there be in BB?
Zwei Dinge sind unendlich, die Dummheit und das All...