Planted Tank Enthusiast
Join Date: Sep 2010
Location: Southern California (LA)
Given your light wattage and your plant and inverts selection, I don't think CO2 is at all necessary. In fact it may prove to be more troublesome than not.
Mosses grow well under almost any light. More importantly for them is the temperature of tank. I have a little over 2 WPG and had three different kinds of mosses die (water temp of 80-82). I know people (as many here do) that have grown moss in little more than a cup sitting on a windowsill.
Maintain your temps in the low 70s and it'll be good. Usually, most people limit their photo period to 6-12 hours. For yours, I wouldn't worry too much about light. Just remember to turn it on whenever you're in the room (which I would hope you do to enjoy your tank!) and you should be ok. Shoot for around 6 hours at least. If you can't make that in person, buy a $5 timer and set it to the proper schedule.
High-tech (high light and CO2 and all the shenanigans) will always result in better growth. But that doesn't mean its better for you. For your purposes you don't need it. You should still be able to have a nice and healthy tank.
Unless the shrimp people know more, airstone won't be necessary...usually used to introduce oxygen in tanks that inject CO2 so the fish don't suffocate. Instead, use your filter to agitate the water and introduce oxygen that way.