@terrenum , it looks like you have single conductors run through braided loom going through that Skintop fitting, The cable type needs to be SJOOW or STOW (those letters will be printed on the outer jacket), with the jacket going into the enclosure prior to stripping down to the individual conductors. You may need a larger Skintop to get it to fit...don't cheat. Also, you should not
need electrical tape anywhere in your installation. If you feel you do need it, it's likely that you have an equipment mismatch or you are not using the correct assembly technique. There are a lot of experienced guys here on HBT that will be happy to advise you on equipment and technique. It's better to ask questions that some may think make you look stupid than it is to not ask the questions and remove all doubt.
Also, if you are feeding your rig from a 50A spa panel, your feed cable needs to be 6AWG minimum, not 8AWG. Assuming you've gotten rid of the ground wire hack to the kettle handle (!), the only serious glaring problem is those single conductors running through braided loom. I think you'd do well to replace that stuff before your next brew.
Before you brew again, I'd also run a continuity check with a meter, with one probe attached to the spa panel ground, and the other probe touched to everything metal in your rig. That means all the pump housings, the kettles, the enclosures, etc. Unless you get a reading at or very close to zero Ω at every test point, keep looking for a problem.
Once you've replaced that braided loom cabling and confirmed your system is properly grounded
with a meter, you should be good to go.