Steerer tube is 265mm uncut

There is external Turnkey lockout and U-turn to adjust the travel between 85-130mm. There is no preload adjustment.

We don't have stock to check at the moment, but we have looked on the manufacturers website and they also picture them with v-brake bosses so they should come through with them.

They wouldn't be ideal, they are a trail fork really. You would be better off with a jump specific fork as they are designed to withstand the impacts. The http://www.wiggle.co.uk/p/cycle/7/Marzocchi_Dirt_Jumper_3_OE_Suspension_Forks_2009/5360045720/ would be a better choice.

Yes these forks do come with V-brake bosses.

The tyre arch is 3 " wide at the widest point so I would recommend up to a 2.3" tyre, 2.5" at a stretch and if you are using a semi slick or otherwise low profile tyre.

This fork uses coil springs and are quite heavy duty, I use them on my Giant XTC hardtail. I wouldn't use them for a 6" travel full suspension bike for big 4ft+ drops but anything short of that and I think they will be fine. If you ride a 4" travel suspension bike or a hardtail and want to hit the bumps head on this fork will do well, with the coil springs you get a heavy duty feel that inspires confidence.

If you dial the fork down to 85mm using the U-turn dial it shouldn't upset the steering on your bike, otherwise it should be fully compatible.

Yes the steerer size is 1 1/8"

If you use the U-turn dial to tone the fork down to 85mm you shouldn't have any issues with the fork. if you use any more travel you may upset the handling.