Single Pair in a 50 gallon

Folks, am planning to setup a planted tank with below setup.
1. Tank capacity - 57 G
2. Temp - 28 - 30 C (this would restrict the plants to be kept)
3. Plants -
a. Lotus or Lily pad (not the dwarf, but which can take high temp)
b. Buce ( it takes high temp, low nitrate requirement)
c. Anubias Nana
d. Anubias
e. Alternanthera reineckii
f. Echinodorus rose or flame red
g. Bucephalandra 'Wavy Green'
h. Bucephalandra 'sp red'
i. Lagenandra meeboldii 'Red'
h. Marsilea hirsuta
4. Dosing using root tabs (to avoid algae bloom)
5. Fishes -
a. Discus (Single Pair) - Checker board
b. Rummy nose (6 - 10) or Cardinals of same count
c. Bottom feeder - still not decided
d. Shrimps - should I? Smiling evily

Now to my queries
1. Is it okay to use root tabs instead of dosing? I have both the setup, however planning for a high temp tank hence the thought process was is it needed?
2. Is it okay to grow my discus completely on earthworm?
Pros - not messy, discus loves them, nutrient value is high
Cons - people advise against it saying they are unclean, and hard to culture
3. Should I use CO2 injection, or go low tech (my preference is to run 1 bubble per sec). But experts please advise.

>d. Shrimps - should I? Smiling evily

Your discus are going to enjoy them, at least :p

Discus only really do well as a pair if they are compatible/mated pair. Buying two young discus and hoping they get along isn't the best path forward. Growing discus in a planted tank is challenging and you won't get NADA worthy competition discus if that is your aim. You can, with luck and making the right setup choices have what appear to be happy discus in a planted tank.

If you want to do this tank right do it slowly, buy a mated pair of adult discus after the tank has been setup and running for ~6 months.
If you aren't doing a bunch of liquid ferts, CO2 injection is wasted IMO.
Most of your plants look like they will be good root feeders, I add a ball or two of osmocote under the root ball of my plants and that seems to be a good, cheap root tab.
I really like Estes Stoney River Premium Aquarium Sand for substrate
You can probably stick to the low end of the temp if you buy adult discus.
Some people can keep shrimp in their discus tank, I can not, my discus like to eat them and will hunt them actively.
An alternative are scuds. You can get them online for relatively cheap and they will live on the plants and roots and in substrate. I think they add something to the biome and create a more complete ecosystem. Plus discus love to snack on any that make their way out.
If you get everything planted before you add fish you can soak/dose the tank with high ammonia levels to kill any snails and sterilize everything. I got up to ~100ppm NH3 by a decimal error when first dosing ammonia and never saw a snail until I introduced them in a fool-hardy assumption that they would be a good addition, they were not, I recommend you avoid my error.

Thank you James,

You are right in pointing out without liquid ferts I won't get plants to flourish, however am not trying to go low end however will yet and gone a balance 😋

Regarding the Royal couple, finding a mated pair and keeping them alone, will it be okay.

And finally there are pairs which show meeting behaviour but hasn't mated yet. Can I go for such fishes?

Anyone tried feeding Earth worms to discus. How successful is the diet.

Just hoping them to be adding some dietary value to the Royal couple.

I've fed them occasionally if I find one in my garden after a rainstorm. I will put them in moist paper towel until their poop is all excreted then cut them up and feed them.

Keeping a mated pair as just a pair is OK and advisable as they will bully other discus in the tank.
I think there are mated pairs, breeding pairs and proven breeding pairs which are: ones that hang out together and clean surfaces, ones that have laid eggs together and ones that have successfully raised fry. Mated pairs are find as a pair on their own.