I'll try some experiments to see, but I doubt seriously that citric acid is effective against chloramines. Chlorine, for sure, but in order to take out chloramines, you need to break the amine bond ,then take out both chlorine and ammonia.

Rocky Mountain White are a great fish, but I'd be astonished if they are legal in California. These are a hybrid of the Auria and the Nile, both of which are forbidden. As far as I know, only the O. mossambica are allowed.

Water depth is not directly related to tilapia jumping out. I keep mine in tanks far more shallow than 36". When tilapia jump out it is nearly always the result of aggressive behavior. Water depth won't make any difference. A larger tank may if the offended party can get away. A lid is the best, period. Keeps the fish in, keep fish eaters out.

Plastic garden screen, or any compound that won't break down but allows water to flow over it is an effective biofiltration substrate. I use scrubby pads. I also use bio balls, and kaldnes. They all work the same way. The problem with most of these is they clog up and have to be cleaned. Using a particulate filter up front help a lot. Kaldnes is interesting as is the aquacube as neither will clog.