I am thinking of buying a Dixon and Bates adjustable height tow bar for our 2002 air suspension Discovery. What is the max tow capacity for the vehicle and does anyone know if the attachment hardware comes with tow bar. Odd question but even the eBay stockist i contacted couldn't confirm and said the max tow capacity for the tow bar was dependant on the spec of the bolts i fitted it with . He couldnt confirm if it came with bolts though.

The vehicle is rated at having a 3500kg gross towing capacity. As for your license though, that depends when you passed your test.

I am not 100% sure to the answer to the other question but I suspect it won't unless you buy a kit.

If your concerned about it but hi-tensile bolts. Most metric bolts have 8.8 stamped on the head but if you go to a decent fastenings shop or ebay you'll find there are 10.2 & 12.9 as well there are plenty of charts on the web telling you how much weight a bolt will hold
If in doubt just go way over the limits & you'll be fine. A few towbar kits I've bought always have 8.8 grade bolts I peffer higher & nylock nuts.
If you passed ur test before jan 1997 u can tow 3.5 tone with a discovery if it was after jan 1997 it gets complicated & really to be safe you need to do a B+E trailer test