Most likely both of these issues are problems with the thermistor wires. Perhaps the connection is OK until the thermistor heats up, or maybe the connection is OK unless you wiggle the wires a certain way. I have seen this before and it was fixed by replacing the thermistor. I wouldn't even look at ...

I have been thinking about this also, but I have a different approach. Instead of compensating for the bed not being level, I have been thinking about using some sort of arrangement of small servos to actually turn the three leveling screws and actually level the bed. You would need some sort of swi...

The newer extruder drive pulleys have a larger set screw that holds better. We still get them from SDP-SI but they have been very difficult to work with and our supply is tight at the moment. Once we have enough to put in stock, I'll post here. If you know another company that makes small spur gear...