There is nothing wrong with using lead-clippings as pot legs* so long as there is a good amount of SOLID physical contact (as mentioned by Sturdag Lagarnathy) between the clipping and the lug, to which the solder is merely aiding and abetting conductance as opposed to the solder acting as the sole perpetrator. *I find most resistor-legs to be too flimsy (ie 1/4w, but 2w clippings from amp-builds are fine); I do keep the clippings from capacitors and diodes.
I suspect issues possibly being...
— BACKS OF POTS: masking tape isn't going to stop a sharply-trimmed lead on the PCB from poking through to the back of the pot. Treat yourself to a popsicle or visit your dentist for some tongue-depressors and hot-glue the popsicle-stick wood between PCB and pots, or use several layers of electrical tape, or try double-sticky taping some milk-carton plastic tabs onto the back of the pots.
— COLD SOLDER JOINTS: I see what looks like a lot of potentially cold solder-joins. Try to reflow 3PDT lugs 1, 4, 7 (and 8). Flow B1k's #1 lug again, too, and any other joints that don't look smooth and mirror-like. Reflow ALL the wires from the 3PDT board, and probably the other end of them at the main circuit-board too. The red wire at the 3PDT-board that goes to the LED looks like a cold solder joint. (I found it difficult to follow your power-wiring between the two boards, as I always use black and red only for power, green for ground in a pinch if I run out of black). Bend the pots out of the way and inspect all solder joints on the back of the board, reflow any unsmooth or dull joints.
— POWER: no effect signal & no LED leads me to suspect you're just not getting power distribution. Inspect all the power points, reflow all of them.
You're getting signal in bypass, so at least you know those solder-points on the 3PDT are good. You mentioned you have got a (digital?) multi-meter, so check to see if you're getting power at the main board. Use your DMM to also check the LED connection, if you've got continuity there, then the power problem may lie in the main connection between the DC-jack and the 3PDT board's power-connection points.
Good luck Yazooligan!
