The game is designed to not operate when the capslock key is on.
Just kidding but honestly, there is no need to yell. Caps indicates yelling.
OOZ has it spot on, for a wheel mouse the wheel is the actual throttle.
I would also suggest a joystick for a few reasons. IF your just learning how to mouse fly AND play AH, you're trying to learn two very hard things and making learning them both twice as hard. You do not need a million dollar joystick. A basic 4 button stick with a hat switch for views will work nicely. Its more natural and then you can concentrate on learning AH.
If you have mouse flying experience and are good at it you can use a mouse but IMO learning both at the same time will only get you frustrated.