When it comes to T5 lighting it's said a single T5 bulb is enough lighting for a tank up to 60 gallons... I beg to differ because I've always found it's best to start out with more lighting then the tank needs because it always easier to "down grade" to find the perfect amount of lighting, then it is to upgrade lighting.
Since your tank is good size I would add 1 or 2 more T5 6500k bulbs to the tank... Flourish Comprehensive is a liquid fertilizer which contains both macros and micro nutrients, and is sufficient enough to sustain a planted tank... For instance, my old 75 gallon planted tank was heavily planted with 2 big Amazon Swords and I dosed with only Flourish comprehensive... The 75 gallon tank had a 48" Coralife power compact 4x65w 6700k bulbs, co2 injection, and 2 canister filters but I was dosing flourish comprehensive every other day the recommended amount....
Root tabs are always a good addition to planted tanks, especially if you have heavy root feeders like swords, crypts, or vals... For instance....
My current planted tank is a 45 gallon long 48"x12"x19....
Lighting - 48" Beamswork Evo 6500k LED, and 36" T5HO 6500k bulbs
Filtration - Odyssea CFS-500 canister filter
Heating - 300w Hydor Theo submersible
Substrate - 70/30 mix of flourite/floramax planted substrate
Co2 - DIY 2ltr co2 system (currently swapping out for co2 injection system)
Fertilizers - Dry Ferts w/ osmocote plus root tabs
In my opinion it's always better to start with more for a planted tank... This is because it always cost less to downgrade... Every planted tank is different even when they're the same set up with identical everything they're still different, which is why I always start with more and work my way down til I get the right consistency in every aspect for the tank!!!!
Flourite as it states does contain some nutrients already in it as stated on the bag... However it's only enough nutrients to get started... Flourite is great because it has a high cation exchange capacity (CEC) which means it's able to soak up nutrients, and then release them slowly to the plants over time. I actually love flourite substrate, I use it in every planted tank I'm setting up! But heavy root feeding plants need more nutrient available to them then what the substrate releases to them which is why root tabs are always a good idea!!!