I'm a little skeptical of S Repens, Monte Carlo and Blyxa Japonica for low tech. Those are the only ones that strike me as really needing CO2 to do ok. They might survive without it, but you want good looking plants right? Otherwise, the list looks solid.
Between the parva and the helanthium, you've got a couple carpet options, but in case you want more, take a look at littorella uniflora and sagittaria subulata.
Nitrate: depending on your livestock load vs your plants, you may eventually need it. I eventually did after NO3 was stuck at 30 ppm for months. Don't neglect micros, and if you need nitrate, you might need phosphate at that point, too.
Last edited by Mike!; 05-21-2018 at 04:35 AM.