I rarely see my pistol either, but I wouldn't really call him noctural, just shy. The watchman sticks his head out of the burrow all day and if i stare long enough at the tank I might catch the pistol carrying out a rock.
Normal cleanup crew, with 2 cleaners, never had any problems.
When I feed mysis/squid I usually shoot a little down the burrow for the pair.
I have had my randalli for about 2 months and have not noticed any growth, but then again I rarely ever see it.