So I thought I found the issue here:
Not an easy part to source, I read that vw charge well over 100 quid for this brake booster and the cheap ebay ones are 45 odd quid and like other ebay parts destined to break. So bought some samco 9mm silicone vacuum hose, very carefully cut the old one off and stuck the new one on, comes to the grand total of 9 quid so cheap easy fix!
Car is definitely running much smoother, however it is still misfiring annoyingly! Thought I had it!
I don't have vag com but do have obd-eleven, pretty decent for a 50 quid thing, although it's by no means the complete package and does have some shortfalls as I show below. This video really helped with what you mentioned:
Obd-eleven just kept showing 0 percent or failed to connect for 032, 033 however showed quite high numbers and started rising from the point of ignition:
I noticed the upper pcv valve hose is loose, and hissing a bit, I disconnected it pcv side and stuck my thumbs over pcv hole and the end to the hissing hose, the number dropped to well into the negative figures. Note that I did this while the engine was running and doesn't sound great when it almost stalls and almost sounds like there is some knock going on when doing this, could just be my ears though. Anyway... ordered some silicone hoses for pcv a while ago but order is delayed until end of the month, just bought a cheap 10 quidder on ebay for now as hopefully that will just prove to myself if that is the issue or not and can replace with the silicone one when it arrives. We're getting there! Slowly!