Sounds ok...I'm actually pretty clueless as to what the problem could be...Try checking the light schedule over there this time of year, maybe some sort of weird light cycle that's confusing the plants and slowing growth.
Wow Kodank...sorry to hear that! Makes me want to hold on tight to my pieces!!!
Anyways, just slap some crazy glue on that bitch, know one will know it's broken!
Goddamn, 9 weeks is forever to autos! They look extremely healthy, maybe something's going on downstairs...What kind of soil you using? And is it planted in the ground? Can't really tell.
Try mixing your own, get some potting soil, some perlite, peat moss, building sand, etc. You should do some research on different kinds of potting mixes...It's easy and much more cheaper than buying shit like FFOF.
Not a good idea, HPS lights get extremely hot, and plastic that close will more than likely melt. But a pyrex glass tube will work, not too sure on where to get one though...You can probably find one online somewhere for cheap.
Sounds like you can use some more ventilation in there...You should use both of those 4in fans as exhaust and just run with a passive intake...It'll probably solve your heat problems.