Mk 1 1.8TDCI Multiple Issues

Hey,

So i'm coming up to that time of the year we all dread, MOT time, and with the changes to the MOT back in May it's put me a bit on edge, so i'm looking for some advice from you more knowledgeable people. First of all I have a very minor oil leak that the car has had since I purchased it, originally we put it down to the hoses between the intercooler and the pipe behind it, which I replaced around a year ago, it helped improve the situation and I don't have a load of oil around that area of the car anymore. However I do still find patches of oil under my engine where I park and over the year it's quite a patch, however I check my oil about once a month and the loss is minimal, I have never filled it up between changes, what I put in at oil change lasts until the next, our second train of though was there is a leak from the breather pipe for the turbo (I don't really have a full understanding of the engine and turbo, I can do clutch changes, suspension, brakes, but never really worked on an engine). Can someone advise exactly where this is and whether that is possibly the problem. I did some googling earlier and when I accelerate hard I get some heavy black smoke out of the back end of the car, which the thread did say could be a symptom of oil in the turbo.

Secondly as you can see in one of the picture, I have a pipe that should be connected to something, looks like a little hose/plug, I noticed today it's become unplugged from wherever it should be, the car still runs fine, but i'd like to get it plugged back into where it should go, I have a Haynes manual but that doesn't seem to be much help, trying to find a good workshop manual that the garages would use but don't really know what's best to get. Finally the last problem I have, is i'm going through a key about every 2 years, is this normal, about a year after I got the car I noticed the key stopped working properly in the drivers side door, at first it would need wiggling then over time it stopped, then as it deteriorated I noticed it started to also happen with the ignition barrel (always worked in pax door though) until eventually I couldn't get the key to turn in the ignition, I had a new key cut and everything went back to normal, however now 2 years on, it's started again, I've lost complete ability to unlock from drivers side, and occasionally it needs wiggling for the ignition barrel to accept it, is this just normal ware for a key, or should I be looking at buying a whole new barrel for both doors and ignition? The key wasn't a genuine ford one as they quoted me £240 for a new key, i'm tempted this time to get a key with remote unlocking (the guy I used said he's pretty sure my car has it and will check before he actually sells me a remote unlocking key) so that will reduce the ware on the key from being used in the door to unlock.

I should just add the oil around the filler area and the top of the rocket cover is not a leak rocker box, it's me being sloppy refilling the oil once and not cleaning it up after myself. Another note I forgot, to attempt to clean it up to put it through it'd MOT I was just gonna get a pressure washer and give the entire engine block and bay a blast in the hope of getting most of it off. Is this safe to do, is there any steps I should do first like unplugging the battery, my obvious concerns are the electrical components, and the force of the water potentially breaking or damaging cables/connectors for the electronics.