problem 5
Sounds like its running into limp mode straight away. This could be down to anything from a dodgy MAF to a simple boost leak. Was there any code on VAG COM? Also if you take your key out, put it back in and start it then rev does it cap at 5k immediately or after a minute?
problem 6 - oil leak - finally found where its coming from, side of sump between a belt of some sort, what's causing this?
The sump hasn't got a gasket, but sealant. You just need to take the sump off, clean and wait for the oil to stop dripping, then reapply the proper sealant. You may have a leak because someone didn't do it properly before you bought the car?