" (I'm fairly sure of this, but I'm kind of a dunce about electrical wiring"
So! Take this as an opportunity to learn Jon!
You have obviously moved on from the "buy a box, plug it in and go" basic home recording jockey to someone of a rather more experimental bent.
Take the issue of lifting a signal earth? Yes, can work but leaves you with a non-standard cable*. Much better to buy some mic cable and XLR plugs and cable sockets and make up an in-line "slug" about 6"/150mm long with the diss'ed shield in there. Then, LABEL IT UP!
Other such "slugs" can be a phase flip, an XLR to TRS/TS, an unbalanced to "impedance" balanced TS to XLR . You might progress to putting things in tins such as iso' transformers, +4dB to neg ten attenuators. A "pot in a tin" is a MOST useful device!
Getting kitted out is fairly cheap. A $50 solder "station" and some basic hand tools, pliers and wirecutter/strippers. A very cheap 2"/50mm table clamping vice is also invaluable.
Most important of all, a digital test meter.
*In fact this action can end up causing Radio Frequency Interference, not common but can happen and there is a simple fix for it. But you need to be able to solder!
Dave.