The Empire is not really well known for their physically accurate simulations. I’d stay away from pure physics sim for a Tie Fighter. Try this for the most basic controls:
Gravity can be applied in a similar fashion:
To make it work better, tie (ehm) it to acceleration or velocity. Ignore it when you go fast, increase it when you go slow. Or keep it off while airborne and enable only when ready for a vtol.
I’d also stay away from Set Actor Location - this would force geometry penetration.