Fuel Guage 06 GS

After a long ride last summer, and one day through an all day downpour. Potentiometer seems to be acting up. Couple of days later, bike wouldn't start, gear position was out of whack. Second, fuel gauge only shows half full. Don't know if if this is coincident, or just the age of the bike? All repairs and preventative maintenance is well documented. Local was somewhat of a help, but bike didn't exhibit any symptoms while they had it - of course!

1. Replace potentiometer with OEM BMW part at $280.00, or - are the ones listed for $150.00 work just as well? Someone on a similar thread suggested getting rid of the Torx bolts and going back with SS hex head bolts?
2. Should I replace the sensor on the side stand too?
3. Fuel strip, or something more invasive?

Thanks in advance
Rob K