...make it more like most driving games, like hold r2 for full throttle hold l2 for reverse throttle....
Ok so i figured it out. Works like a driving game now.
Tldr:
Bind right trigger to analogue throttle axis, ensure full range option is selected (not forward only).
Bind left trigger to Thrust axes, ensure inverted is selected (so it works as reverse).
Enjoy having full control:
Supercruise 0 to 100% on right trigger (analogue)
Note: reverse does not exist in SC and letting go of trigger is same or even slightly faster, than the default controls using down throttle.
Flight mode 0 to 100% on right trigger (analogue)
And 0 to -100% on left trigger (analogue)
Both triggers drop to 0% when let go. And analogue means you can half press for 50% power etc.
Long winded explanation, in the hopes it might help some other noobs:
For the throttle, having "forward only" made it so right trigger would sit somewhere around 50% (blue zone) when released. Which I didn't like. Enabling "full range" made it so that when I released the trigger throttle went straight to 0%. (This is having trigger bound to forward/backward throttle axis (analogue), so I can press it 1/3 the way in and throttle is at 33%). In flight mode this set up behaves exactly like thrust would.
Supercruise has no such thing as reverse or even brake, just 0-100% throttle. Right trigger effectively controls all forward/back motion in SC. (Even tested letting go of trigger vs holding "down throttle" on a key bind, they both stop in the same time, so down throttle bind is not needed for super cruise (given the above right trigger config).
Now for reverse/backward thrust. Using the backward thrust bind on left trigger made it (digital) so when I slightly pressed trigger it was 100% and let go was 0% there was no in between.
So I bound left trigger to the analogue Thrust axis and used inverted (instead of regular), now I can use left trigger to go from 0 to -100% and anywhere in between.
I also have Y-button + D-pad left right up down for 0,50,75,100% throttle for when I cbf squeezing the trigger. Also I recommend putting lasers/main guns on weapon slot 2 (left shoulder button), makes it more comfortable to shoot, "thrust" and manoeuvre at the same time.
Works like a charm (like a racing game as you put it).
Thanks guys!