I would start with a fresh scan and post any codes, code numbers not descriptions.
As for the maf; what is the part number and what brand did you buy? A high quality Bosch maf; is recommended, many aftermarket version do not perform correctly and cause drivability problems. Since, this is a variable you just changed; you might reinstall the old one and see if that helps your problem. Reading live data from the maf and comparing the two; would be a good idea.
Otherwise with 1.8T sluggish drivability and surging issues; tend be related to the boost control systems, not working correctly and boost/vacuum leaks, are usually the culprit. Diverter and other boost valves; are typically worn, in soft failure mode and it is recommended to try testing them using factory service procedures. Read more here:
You have a TON of codes! How long; has it been, since you did a scan? If it has been a long time; these could have built up over the years, you could clear them and see what comes back. You have quite a few codes; that are directly related to the boost control system, these could be directly related to your sluggish drivability problem. At a beginning point; I would make sure, your charging system is working correctly (e.g. battery, alternator, wiring, etc.). If you have a low voltage issue; it can cause, all the computers to freak out and throw ton of codes, as they cannot work correctly with low voltage.
Ok, so which boost trouble code is it? Please, post the codes; not descriptions, this removes any possible confusion and we are on the same page, thanks. Then, I would start looking at the definition; on the ross tech wiki and start testing that problem/valve, based on the service manual procedures.