I have several of those, but first 5 things I will do when I becomes the new boss at Nordeus:

-Scout market - Each bid costs more tokens than normal bidding
-2D simulator
-More cross-server interactions
-Bigger leagues (16-18 teams), and Champions League B (Europa League), as well as custom tournaments
-Longer seasons (6 weeks with 1 week break [no games scheduled])

Longer seasons with about 18 teams will take about 34 matches to be played, Maybe Top 4 could go to CL, 5th-6th plays in the CL-EL qualification playoffs, 7th plays in EL and 2 more teams promoted. That means 42 matchdays are required.