It's definitely a heavy handed dose and I would not use the schedule. 1 thing to consider, all things simplified, the reason you do 50% water changes is to reach a target dose. You can't have more than 2 times the weekly dose. So if you want to target 20ppm NO3, you dose 10ppm weekly. Also, ignore generated nutrients, always assume the tank is 0ppm. Finally, use correct gallons. That 10 gallon tank may have only 8 gallons in it.
This is a hot dose also. I would target .4ppm Fe as proxy. We don't assume target doses with micros. It's always a weekly dose. Is it CSM+B? PH matters for the chelate.
100%, sadly. But if it is fun, use it. But it's definitely an issue and just not sufficient to keep CO2 levels consistent.
Possibly, you want the light to be the limiting factor.
Unlimited nutrients
Unlimited CO2
Light sets the limit while the most demanding plant's needs are met.
Your specific plants shouldn't demand alot.