I am not sure if someone already suggested these things, but here are two of my main suggestions.
What about more games in one week? Or another setup. But having more games played in one week has alot of advantages for managers, especially new ones. This way (new) managers won't have to wait for three months for a new season to start if they aren't going to be succesful. A week could (for instance) be devided in two weeks. Monday - wednesday: 2 regular games and a possible friendly. Thursday would be a day for internationals and friday - sunday for two more regular games and another friendly. That way you have two updates in one week. New players would feel they have more influence in their game, cause they see more results in training and more money to spend, cause they got more games played. It speeds up some things and players might feel connected (at least sooner) to BB.
I alo think the training page is in need of a change. It's not very transparant for new managers. Why shouldn't a manager be able to set out how many trainees he wants trained? If I want to train 4 trainees I should very well be able to. Each manager should be able to select who he wants trained and what he wants this player trained. For the training to take place a manager should only have the player play 48 minutes on any position. Training doenst take place in a game in real life, so why should it be that way here? Training a trainee shouldn't have to change the way a team has to play. If I want to train secondaries I still want to play a center on his best position. It just doesn't make sense.