Q: Is it possible to add more then 10 models to RC Flight Log?
A: In version 2.0.1 there is NO maximum limitation of models.

Q: How can I trace the amount of fuel used by the aircrafts?
A: Use field "Tanks/Battery" to trace the fuel consumption.
You can add the fuel amount as e.g. liter, decilitre, gallon, tanks etc. It's all up to you.

Q: Is it possible to use the last flight log as "default" values when adding new flight logs?
A: No, but it is a very good idea. Will be fixed in the next version.