LMFAO. I was going to post up about that one myself.

Forget your engine change plans, neither of those engine will go in a Mk1 Focus without a completely custom (read: expensive) rejig of the engine bay. Only 1 person's tried putting a Focus ST engine in a Mk1 Focus and it just turned into an expensive disaster.

The reason you have a shiney black door mirror as well is because it's a cheap nasty pattern one so it doesn't have the facility to remove the cover and replace it with your original coloured one. Still, assuming it fits, it's a door mirror so will do you to start with.

The engine management light os probably a lambda sensor and the high speed shaking and play in the driveshaft means you've shagged a universal joint tripod (almost certainly the driver's side). If you remove the driveshaft from the hub and pull it out of the universal joint casing there is a tripod assembly with 3 bearings on it, I'll bet one of them is missing and still in the universal joint. I have a full set of shafts for sale when this turns out ot be your problem.

Dude your reputation precedes you and you will ALWAYS be perceived as a complete and utter bullshitter. Live with it.