With your filament sensors, they’re very easy to test. Do one at as time, tigger the sensor, now run M119. What feedback do you get? Now un trigger the sensor, M119 what feedback? Sounds like they may need inverting.
In terms of your heater issues. Did you try replacing your heater cartridge? Id believe a faulty Mosfet if I’d seen one before.
Sorry I didnt get your previous messages. Our email notification system has been down, meaning your posts we’re unread. Going through them now.