forge is on the ground level. found a couple recipies when I was in there. don't know what all is required b/c my bruiser is a provisioner and the recipies are for tailor and armorer (gee, go fig, its armor :-P ). but the recipies do require you to have a Blood Iron Ore which is a rare drop in the citadel (only found 2 or 3 when I was in there, and I lost track of how many we killed, but it was over 100, maybe close to 200, so looking at 2-3% if not 1%).
finally, no, a 45 cannot get there easily. several 38 heroics in the way, not to mention a couple in the building where the forge is.