KermadecAirways

Coturavi Airways

• Ultra-short routes are not very profitable, if at all.  You are getting smacked from low ticket prices and repeated landing fees.

Aerotal Airways

• The only good thing I can say about the 1900C is it is better than the King Air.  Why are you not using a slightly bigger prop like an ATR-42/72?
• BAQ has 4 completely unused gates that you are still paying full price for.  I doubt a fully loaded 1900C can pay for all that.
• Short routes again.

Tasco Air

• Short routes again.
• Two families will increase your maintence cost.
• I really doubt the (tri)slanders are paying for themselves.  The fuel usage on the Trislander is about the same as ATR, and it has less than 1/5 the seats.

If you want to run a small airline, I heavily suggest sticking with ATRs or DASH-6/7/8 as you aircraft of choice. 
Most of your smaller turboprops have the same fuel burn as larger ATRs.  So a half full ATR will make more money than a full Trislander.
Also, be sure to immediately ditch any unneeded gates. 
Finally, SCAM the daylights out of you PAX.  You need to compesate for low short range ticket prices somehow.

Short term routes are good to fill up unused hours, I have two and with over 20 daily flights at one and more at the other. They bring a smaller profit and add to aircraft's return.