Hello Alex,
Thanks for being in touch with the forum.
Reverse sensors? Diagnosing this will require half an hour with a meter to check if you have 12v at the sensor point etc. - having first checked that the fuse is intact and is making good contact. Don’t simply look at the fuse and decide it looks OK, but also spray some contact cleaner in the holder and give the fuse a wiggle to ensure it has a good contact. Are the reserve lights working?
Re stop/start not working - could be a classic symptom of a failing battery, so it’s worth getting that checked as the first port of call.
Perhaps you could let us know how you get on.
Kind regards,
Gareth.