The first one, I think is true, GMs approve new accounts but number of new managers decreasing, and the old ones finished because of the game performance, or because of obsolete of it - there is no new features, maybe of competition (14 online basketball managers at the network
http://www.onlinesportmanagers.com/games/basketball/)
I do not know how old are you, but for todays teens the game should spark, visual aspects should heave been at the first plan (for me is OK) I know that costs a lot, we should find founder (maybe supporter should be cheaper), more advertisment, I think in the game are a lot of developers which can help, maybe some PR Manager in staff will help.
this is my only loose thoughts