You'll have unstable readings on resistors if you are moving the probes along the legs. If you are steady, it shouldn't do that.
You should test your capacitors to see if they are still ok, since Andy had doubts : he may be right.
Potentiometers are built like tanks, you shouldn't worry about them being broken. Their values is the most important thing, and their wiring : you see their back on the schematic.
Did you correct the soldering ? There was still some suspicious pads on your last pic.
The ones in the signal chain should be fine, the only one that could be damaged is the filter cap across the power supply (C17, 47uf). Resistors are nearly indestructible, as are pots and standard caps. Transistors can be cooked with too much heat.
The board is looking much cleaner by the way. Nice..
If you can, pull the entire circuit out of the box to check it. I often use a piece of cardboard with holes in it to hold the pots and switches while I work, before I box it up. Sometimes I even label the cardboard to help avoid stupid mistakes. Much easier than working in the box - use the holes on the box as a template.
If your multimeter has a continuity tester, move through the wiring check that nothing is shorted / not connected where it should be. i.e. output jacks and switches. If it works on the bench and not in the box, then you probably have a short to the box.
