She also has a hole in her back plate... and I saw a mite go in it

I thought she had a motl sac, but it turns out she doesn't... she's been pretty lethargic since I got her months ago... Although secretly she likes to trash the tank ocassionally.
That's part one of the problem. Here's part two:
My tank molts... BADLY... the food goes fuzzy in a day or two, and now I also found mildew on the glass in the back corner... In the corner Bhaal has been burried for weeks, and I'm possitive he's down for a molt!
I also found a small gnat flying around in the tank....
Now, with mold, mildew, mites and a single gnat, I want to dig Bhaal up.... before things get to him! If they haven't already killed him

My husband yelled at me though and tells me he's safer under the sand...
I would like some opinions here, dig him up or leave him be? The tank smells like the crocodile part in the zoo! The water dishes are gross... But I'm too afraid to collapse Bhaal's cave if I move things around too much >.<
HELP!