Thanks Marcus! Yes, the derailleur came with the bike. So, I'll keep trying. Can you elaborate on "you should not use opposing cogs/chainrings"? Like never ride in those combinations or never tune with the gears set in those positions?

F|MTNdude, Love that YouTube channel. Calvin Jones is the man. Got the basic tools, too (and then some! ). I think I gotta just keep after it and keep learning...

andrewclaus, I did wonder about the pricing and the components... That's why I'm curious about upgrading. The bike itself is good--good design/angles. I've upgraded the BB with good results. Might do the brake calipers. Definitely considering the crankset since it has some wobble. The new BB is a nice, middle-grade Shimano, so maybe an upgraded crankset will make for less wobble. Who knows.

hokiefyd: thanks for the detail--really sound advice. I'm going to try tuning to the middle crank cog. Re: "Another option, if you just don't like how it works, is to change your front shifter to a non-indexed one. That way, you can "trim" the derailleur left or right to move the cage slightly to prevent rubbing." Can you explain further? I'm a fellow Virginian, btw

JonathanGennick, yep, it's sounding like that's front derailleur life