So i currently own a petrol mk3 powershift that i was told has a 'dry clutch' and why the gearbox has so many issues and i have had to have the clutch pack changed already, so the diesel 1.5 and 2.0 have a wet clutch? are they just as prone to issues? i was planning on upgrading to a mk4 Focus but decided on just upgrading to a 2015 or 2016 plate diesel for now instead, also whats the difference between having a dry clutch powershift and a wet clutch? does the wet clutch have fluid? from my understanding the wet clutch version is much more reliable and less problematic but needs servicing regularly.

The wet DCT Powershift is certainly more reliable, but you must service it as per Ford's recommended intervals. That includes ensuring the previous owners have done the same. It isn't part of the regular service schedule so should have separate documentation, at a cost of around £300 every 3yrs/36000m. 

The service consists of changing the gearbox oil, that's the most expensive part of the job. It can be done on your drive if you are a DIY mechanic, there are no specialist tools required, just space and a means to raise your car. 

The difference between the two is reliability, I wouldn't touch a dry clutch Powershift. 

I had a 2017 1.5 with the Powershift and it was spot on, never missed a beat.