Yeah quite a few. I have learnt a lot reading through everyone of these as I experienced every issue going. Mash temps all over, couldn't get a boil and loads of grain in my wort.
Hopefully this can help what I have learnt from the other thread summed up.
PID is really needed for mashing but does need to be adjusted for volume.
Calibration does need to be done but not from freezing water to boiling point but more the temps you use so let's say 65c to 75c for mashing and mash out etc. So first point would be at 65c and second at 75c then that range will be the most accurate.
For the grain in the wort I am going to buy a bag and just put the bag in the mash pipe.