Yea you can run gears on it, I run single speed on mine with a locked out mech.
I think the horizontal droputs are really nice aslong as you have the tensioners, all I can see wrong with them is its a bit of a bugger to get the wheel back in but other than that, they're good! :lol:
I'm about 5ft8ish and this bike suits me perfectly, just the right length for me, although you can ajust the wheelbase slightly, I run mine at about 1030ish.
Aaron.