1. Bps is not a good measurement of how much co2 you actually have in your tank. The PH/KH/Co2 chart is good, but is not always accurate. Your best bet is to use PH drop to determine your Co2 levels. Aim for a 1 point drop in PH. Measure right before co2 turns on and right before lights turn on. A 1 point drop is equal to 30 ppm Co2.
2. Regular water changes are good for planted tanks. As Maroman said, 50% weekly is the general recommendation. It partially depends on how much you are dosing. With low dosing levels you can get away with longer between water changes. But it's better to do them more regularly.
3. You want to do the Macro ferts (Nitrogen, Phosphate, and Potassium) on one day, and the micro ferts (flourish, trace, iron) on a separate day. If you do them the same day the phosphates will react with the iron and other trace elements, rendering them useless to the plants. Also trace and flourish are both a micro fert mix. They do essentially the same thing, in probably slighty different ratios, so it's not necessary to dose both of them.
4. I'm not familiar with the Giesman lights, so I can't give you good advice there. Maybe someone else can help with that.