I found out that you dont need 10mm frame strenght. 7-8mm is enough. but you need place to hide all the cables so thats why I made it 10mm.
Also you should take off the cover from the ESC and unsolder the cables to replace them with shorter ones.
the LEDs are just for fun but look cool. Anyway you can go with smaller motors as those are the most heavy part of this quad. Then you should modify the mounting part of the frame.
I used multiwii 2.2 with default PIDs and everything is working fine. Maybe I will try to tune the Barohold function but usually I fly just acro.
Also the flightcontroller is set up for Graupner/JR SummSignal so you need only 1 cable from the receiver to the flight controller. This helps A LOT on such small quads.