For your tank 1 BPS is a good place to start. You won't see much change in pH and the drop checker will stay blue but letting the critters get used to CO2 slowly is a good idea. Then increase the CO2 every few days watching the fish closely. The first week of setting the CO2 is hard as you aren't seeing much in the way of a pH drop but better to go slow and never see CO2 overdosed fish, right? Since you are planning a low light tank you don't need to be pushing as much CO2 as possible. In my bright tank I need to get a drop of more than 1 degree from degassed tank water to pH at the start of lights on but a low light tank would be fine with less than that change.
To spot treat I turn off the pumps and use a syringe. Let the tank cook for 20 minutes and then turn the pumps back on. I would start with just the suggested daily dose, 1 ml per 10 gallons, as your algae isn't horrible. You will see the BBA turn pink/red/gray in a day or two and then algae eaters will be able to eat it. This can be done daily of course but repeat at least weekly even if you don't see any BBA for a while to destroy any new growth that starts up. This may damage new Anubias growth but they should recover fine. Just remove BBA infested crypt leaves they are likely on the way out anyway.
Since you are taking charge before a really horrible case of BBA got started I suspect the lower lighting and length of day with some CO2 and NPK and you will have healthier plants in a month or so. 2 bulbs of PC is low light unless you have terrific reflectors, after you get this under control maybe you could add in the other 2 for an hour a day and see what happens and increase by an hour every week or so.