Two bulbs may be more than the tank needs, try using only one for right now.
Zero nitrate is not a good thing, plants need nitrogen and nitrate is a great source. With bright light and CO2 you need to be dosing the tank with a complete fertilizer that contains NPK+traces. See the sticky on the Fertilizer forum for details.
I would leave the CO2 on all the time rather than depending on your schedule. Just pull back a notch if you are concerned about the oto. You might want to let the HOB filter splash a little as this tank hasn't much water surface and planted tanks do need good aeration same as any other tank.
Don't replace the filter media, rinse it with old tank water. A new tank can use all the bacteria it can get! As long as water flows through and it isn't breaking apart keep it. I have the sponge that came with my sump over 10 years ago, still hanging together!
I would definitely add the shrimp, if nothing else they are the cutest things!