Adjust the lock stops so they don't. That's what they are there for.

Warning, they are very noisy

We had one Freelander do that twice, never experienced it in any other, but I won't trust leaving the keys in.

Are they covered in mud/water/ice?

Definitely something very wrong, you should be getting 15-20. Any idea why the previous owner sold ir? It sounds like time to go back to basics, timing, points plugs etc. Don't forget mechanical faults can cause poor mpg, especially binding brakes. Can you get it to a hill, will it roll down in...

Look at the speedo and do the sums

I think it is down to the offset of the wheels, rather than what they are made of. This makes the alloys stick out further , so the studs aren't long enough, that's why you need the later bracket.

There should still not be only one wheel spinning. If the centre diff lock is working, there should be one wheel on each axle (not nesseserily on the same side!) spinning

If you are moving, yes

WRONG WRONG WRONG. Wind up can and does occur if you drive around on a high grip surfice with the centre diff locked, and that can lead to big bills. I do agree though that it is best to engage diff lock before you loose traction, so that momentum is not lost.

Have you tried it in diff lock?

Unless your original diagnoses was right, and traction control keeps coming on.

What do you mean by "doesn't drive"? Won't move, or jammed up solid and engine stalls?

Assuming the ice breaks as you drive in, enter the water then stop suddenly. This will send a bow wave underneath the ice. Back up and repeat until the ice starts breaking up. Still take care, a chunk of ice could easily puncture a radiator. 10mm may be a bit ambitious.

Please do not wash it in a ford, not environmentally friendly.

Fuel Burning Heater?

Unlikely to be metric on a Series II

Why do you want a Sport? They ride a bit lower, so a bit less clearance, and the suspension is stiffer, I found the ride uncomfortably stiff (and I drive a Series III!) although I believe a lot of modern GTis etc are worse. There is no difference in the performance.

I assume you are talking about "pre-used" Very difficult to be accurate about specs, as it keeps changing in detail so what was standard one year may have been an option next year.

Headlight washers tend to be high pressure and use vast quantities of water. I doubt a standard screen washer would have much effect, unless you use it with a wiper, far better system, but stylists don't like them.