I’m probably not the best person to ask. Watch some of Silk’s old settings videos. The most import thing is to bind pitch to your keyboard(most people use spacebar), so you can loop continuously. Flying on M&K is a lot less intuitive, but I think it’s worth it in the long run to learn.
I’ve never played GTA on M&K so I’m not sure. The keybinds are customizable so you could probably set it up like GTA. It’s all personal preference, the only thing you 100% need to do is bind pitch to your keyboard, and probably yaw/rudders as well.