It does get hot, like any halide fixture. I would certainly be concerned at having it TOO close to acrylic.
The bulb it comes stock with is very blue, I would try to change bulbs if you do not like the very blue look.
The clamp and fixture work fine and I see no problem using this for a small application. I have gotten poor growth with sps, and I think this may due to water quality and a very blue lamp. My anemone does fine, tho.
-A