Simple is always good. First thing I did when it started acting up was check oil level and the air filter. Oil in on par, clean, and the machine has a shutdown mode if it gets too low anyways. Pulled the air filter and although it looked pretty clean I hit it with some compressed air anyways. Machine's mostly been used in a clean, concrete floor shop, and very little dust came out of the filer.
Was able to replace the inline fuel filter today and although the engine still doesn't sound exactly right and is revving/ galloping a bit, it did let me burn two rods with a good stable arc and no issues. Unfortunately this doesn't really mean anything. Tomorrow it might refuse to idle properly let alone run a bead. I'll inspect the spark plug tomorrow & probably just replace it anyways.
Re: Ethanol -- Currently shopping a good container / spigot & then I'll get that crap out of the gas from here on out.