I was thinking it would streamline things if you were able to access a players stats on his player card. Maybe an extra tab to go along with the others.

Do MFN Players have 'schemes' or 'styles'?

Like, are some QBs WCO QB? Or are they all just QB and can equally be placed into any and all Play Books?

Because seeing the list of Systems they are familiar with and to what degree would be cool to try to get the most synergy out of your team.

Which, to tie in to the OP, would be a Tab on the Player Card.

You should be able to deduce this from player ratings. There are no QB designed runs, so each QB basically plays the same role in the offense, every offense. If you are throwing med/long a lot or you run the roll out plays, then you need to pay closer attention to your QBs attributes and shift your weights to compensate for things like scramble.