RE: Rebuilding the tank
I am not up to speed on the Stores in austin anymore, so I can't help you there but I wouldn't doubt that a Austin MAAST'ard would help you out with a live sand culture.
As far as the other questions - the eopxy your talking about is safe and will make your rocks more stable. I used it to attatch some coral frags once, and when I wanted to move them, I just broke it right off the rock. I am not sure it's what your looking for in peace of mind.
As far as your sand goes, if your tank crashed and your restarting it, It might behoove you to siphon out your sand bed and start a new one... that is just a thought, i would have others weigh in on that. I personally am a sand bed/dsb fan, but uif you don't keep up with them maintenance wise, they can be a time bomb.
"Maybe in order to understand mankind, we have to look at the word itself: "Mankind". Basically, it's made up of two separate words - "mank" and "ind". What do these words mean ? It's a mystery, and that's why so is mankind." ~ Jack Handey