More will come but the most important is the mounting of part on heatsinks.
All heatsinks mounts 1 mm above the pcb. Just put a cardboard under the heatrsink when you solder.
Non of the regulators need insulation nor heat compound.
T17 and T18 needs to be insulated with mica washer, kapton film or silicone rubber. This is a low power application so all material are equally good. No heat compound is needed.