The update on "misfire"
First thing is that I ran a can of DieselPurge through the engine (Thanks much for instruction video!), which seemed to improve things slightly. Just slightly. I then pulled codes and got a MAF code, P0101, and an engine speed sensor code. Cleared them with vagcom, drove for a bit, and then code P0101 returned. No engine misfire codes however.
Before I just drop a new MAF sensor in, I have heard that some of the things that can give confusing readings are any leak in the intake (i think I know someone with a smoke generator to check for leaks), and/or a stuck EGR bypass valve. PCV valve too? Will try to check these.
Also, because this issue began immediately after a refuel at a station that probably doesn't do much diesel business, I suspect my lift pump with 240K on it just might be a bit gummed up. I think I will change that as a service item, just in case. Got one this morning, so will try it tonight. Will keep you guys posted. Any video on this install?