Chris, I have a few suggestions for adding to your comprehensive welding guide. Just like the average car driver doesn’t have to change spark plugs all that often, every MIG welder has a liner inside the long wand that will eventually accumulate grit and cause start and stop wire movement. You’ll squeeze the pinch rollers tighter, change the end tip, and keep scratching your head. I replace one at work about every two months, as well as replacing a felt wire wipe before the rollers.
Next, when welding across a span that has low contrasting reference to what you are joining, I find that even with my $200 darkening helmet, the most consistently straight bead coverage is to traverse from 12 o’clock to 6 o’clock towards yourself, no matter how I had to rotate the work to accommodate it. You can prove it with an unlined sheet of paper. Put on sunglasses, and see how straight of a line you draw across versus towards you.