Sharon,
There are no dumb questions just dumb answers!

I will give comments of you questions in the orders they were ask;
1) hydrogen evolutioon can occur when the limiting current density is exceeded, that is when the current is too high and the stirring is too low or the concentration of copper ions is too low.

2) anodes, where oxide growth occurs,  can yeild  Cu(+1) oxide films that rub off easily and there is a dull yellow color,

3) high Cl can cause pitting and yield undesirable deposit properties, check with the vendor for best operating range,

4) high concentrations of bubbles can cause turbidity, nobody knows what size/concentration of bubbles causes concern. It seems to me that a plumbing system could be constructed so bubbles do not occurs, many people use continous flteration with success.

Sorry for the late reply.
Richard Haynes
609-497-4584