Next item is the tank.

I have seen tanks that are drilled and not drilled. This one was drilled from the bottom and had overflow tanks in each corner which fed a wet/dry filter and a protein skimmer (topics for later There were also some small scratches in the inside, I assume from moving rocks. The edges of the tank (joints) were not covered with wood trim.

Questions:
(1) Is drilled a good thing or bad?
(2) Bottom drilled versus side drilled?
(3) Can scratches be removed from glass?
(4) What is the best method for cleaning the glass (inside)?
(5) Is there a reason for not covering the joints with wood trim?