Go to the options menu and look at the (huge and frighting) key map.
Choose the flight control option and make sure you are on Mouse and Keyboard
Change the buttons you want to do the things you want and change the X,Y axis of the mouse to do the same.
Go back in-game and test, repeat till you have the control tweaks you're after.
I can't give more details because I'm currently not flying, but when you've played around with it for a bit you'll get the idea.