Transfer deadline will make the game more enjoyable... For example, day 1-5 is the summer transfer and day 14-16 is the winter transfer of a season. Negotiation can be done at any time, but the player will be added to the squad if the transfer window is open, otherwise on the next transfer window opens. Scout and Recommended player can join as the same as negotiation system. Only player from youth club can join to the squad at any time.
The rules is quite familiar to FIFA...
I will eager to see this updated....