First off, I wanted to say we have reached 1000 businesses!
I think it would be weird to have tiny airlines that normally operate commuter planes flying 737s. I’m hoping the size column will help with that but I think some time needs to be dedicated to implementing airline mod. Is it possible for the size column to be a direct link to the contracts they offer and the type of planes they fly? (i’m clueless about code, so I don’t know if that is even an option)
Well afaik the size only influences contract demands / offers. Which would mean number of flights.
But airlines are not supported yet 
I was saying some time needs to be put down for airline mod and making sure everything is realistic.
I think ACEOMM wouldn’t work like that.
For example if an airline has Cessnas or DHC-6 IRL, This airline will only have these aircrafts with liveries. It won’t have BAE or 737. Same thing happens for other airlines which have 737 but not have DHC.
You are right, time needs to be spent on this
Wow! Impressive 
I have a couple of suggestions on the British side of the pond 
BMI regional (aircraft ERJ145/35)
Virgin Atlantic (B747/A320) whenver the 747 arrives in game
Isle of Scilly Skybus (DHC6 only)
Easyjet UK (A320NEO,A320,A319,A321)
Biritish Airways Cityflyer (E190/70)
Blue Island airlines (ATR72)
Eastern Airways (E170, ATR72)