Ditto - We've got my old Dawes Discovery over here and I've been thinking about trying to get some fatter tyres & a set of suspension forks on it as the roads over here in our part of Andalucia are either tracks or full of pot holes.

Yes, the fork includes the cable and the handlebar.

Post mount is for disc brakes - no canti bosses.

160mm standard without an adaptor
I think max is 180mm with an adaptor

The poploc system operates in a similar way to your gears. A single independent lever pulls a cable which twists a knob on the top of one of the fork arms. Thus the poploc is either on or off. When "on" the forks are locked meaning you don't get pedal induced bob when you climb.
If you decided you did not want to install the poploc feature the forks would just behave normally. (Looking at this feature on my Reba shocks you cannot operate it by manually by twisting the "knob" as there is nothing to grip onto)
Having said all the above I would recommend the poploc feature it is easy to install and effective.

No. You can not put it on a bike with V brakes. This model is only suitable for bikes with disc brakes

Sorry, no.

They have Post Mount disc fittings only

Due to the price we have sold a large quantity of these forks, if you see an item heavily reduced that you want, we would suggest ordering sooner rather than later to avoid missing out.

Sorry, we are not a Trek dealer so are not familiar with that model. This fork has an 1 1/8" steerer though, so should fit mtb's with an 1 1/8" steerer. Fitting requires cutting of the steerer tube, plus removal and fitting of a crown race, so a few specialist tools are required, if unsure we would always suggest taking to your local bike shop.