Vals and some swords actually are more med-high light requirement plants, at least the vals and swords that I have are.
I do not regulate the CO2, it is really not that necessary unless your goal is the most increadable planted tank. My tanks are fish tanks with plants in them so my main focus is the health of the fish but my plants are healthy, grow well and look pretty too. Plants do release CO2 not O2 at night which can make your pH fluctuate depending on your water but it has never been a problem for me. Once you set up the CO2 take a pH reading in the evening after the lights have been on for awhile and then again in the morning BEFORE the lights come back on. The tubing I stick into the intake of my filter so the CO2 has a chance to dissolve and not escape at the surface.