Aircraft Flight Problems

Hey all, having a few problems trying to code an aircraft and was hoping all you smart folks out there could give me a hand. The aircraft mostly works fine, it’ll accelerate/decelerate and turn but there are three things I’d like it to do which I can’t currently work out. I should also quickly mention that I’m not worried about getting too realistic a feel as I’m on a bit of a time crunch, arcade-y feeling is fine. Overall I basically want it to look right, even if it’s technically nothing like how the real thing would work.

Firstly, it’d be nice if the aircraft would naturally start to move towards it’s forward vector, even when not accelerating. Basically to try and get the feeling that the tail fins are actually having some effect and actually biting into the air and changing the aircraft’s path, rather than drifting sideways like a star fighter like it currently does. Ideally this would be an effect I can scale with a variable if possible.

Secondly, when losing speed, it of course falls. This isn’t a problem on it’s own but it just drops straight down like a rock. Of course that’s not really how that works so for a simplified way of getting it to look at least kind of realistic, is there any way to get it to naturally fall into a nose dive? I tried changing the center of mass but that only seems to have an effect when it’s already touching the ground-in the air it does nothing.

And lastly, how do you work out maximum speed? Ideally I’d like to cap the maximum speed, and to have a way of getting a percentage of that speed (ideally as a float that goes from 0-1 as that’s probably the easiest way to work with it).

Thanks in advance!