If it's a model YCSYxxx-xxx-48T series controller, then it won't be programmable through the BBSXX programming cable. What you want is an LD-AK-xxx controller which appears to be programmable. I say "appears" because, while I have connected my LD-AK-011 (750W/Bafang H640 motor) controller...
Typically you shouldn't need to remove derailleur. Shift to the next to smallest cog on wheel. Rotate derailleur arm back (which would be forward) with one hand and remove wheel with the other. Sometimes I unmount the disc brake bracket when reinstalling wheel as it's easier to navigate the...
Assuming something wrong in the motor, you could get new motor and swap out the core without needing to respoke motor into wheel.
https://www.greenbikekit.com/electric-bike-kit/rear-bldc/rm-g020-swx02-bafang-hub-motor-750w-500w.html
I have the same kit on two bikes. Though never had a motor...
I second the Microshift Advent. I have over 8000 miles on mine. Paired with the matching ball-bearing shifter, 11-42 cassette, and a KMC chain. This is on my Bafang hub-driven Mongoose Envoy cargo bike. I've only replaced the chain and cassette once over those miles.
I've built a few wheels. I found success going to FreeSpoke and picking a known rim and hub and using the calculated specs for spoke length.
https://kstoerz.com/freespoke/
Yes. I've bought two Bafang SWX02 500W rear kits with Samsung batteries. One installed on a Mongoose Envoy and the other on a Townie. Nearly 9000 miles on the Envoy and nearing 4000 on the Townie. Shipping was two weeks to Charlotte NC
My guess is your control board went out. That's what happened to our recumbent exercise bike. There may be a exercise service company in your area who could repair. Or maybe someone has posted a video on YouTube. Good luck!
Everybody knows thumb throttles are awesome! They're an advanced ebike rider tool improving safety, navigating otherwise difficult passages, and a get-me-home backup should there be drive train or rider inoperable failure. Broke my hip on a fall. Thumb throttled home. After rain, creek too deep...
Definitely could try a larger chain ring up front.
I have a 42:tooth chain ring on my hub driven/cadence sensored/thumb-throttled 1x9 Electra Townie. The cassette goes from 11 to 36 teeth.
I'm constantly rolling through the gears though rarely get to the 36 out back.