In my opinion I think root tabs will not make up for lack of organic substrate over the long haul. You can see a boost in initial budding and leaf production with fertilizer tabs, but trace elements and long-term carbon/nitrogen stores will be limited in a new setup. You can coax plants to put on heavy vegetation, and then not provide enough long-term support to keep them from spotting and developing chlorotic patches on lower leaves. Now much of this depends on the type of plants you select to start the aquarium with, many good aquatic gardeners start out with all stem plants to get things going and then replace with other forms over time, as the system adjusts and collects detritus (decaying leaf matter/fish wastes/light gravel scum) in the aging gravel bed.
I think a great mix for your tank would be to actually plant it with slow growers who are easy on light, like heavy Microsorium P. (java fern) and Anubias of any kind planted very densely. Keep fertilization to a minimum, Id recommend light dosing with the Pink and Blue bottles of Kent's Pro-Grow and Micronutrient support, these work well in my systems and are the only two fertilizers I use. To start of with a nutrient poor substrate, why not try plants that won't pull from it as fast/ Then you won't find yourself dosing so heavily in a Nano and having all the green water you fear. this is a good approach for the lighting and CO2 non-injection you've mentioned (which can be nicely compensated with a few respiring fish).
let your substrate slowly collect over time; dont load it heavily with high-nutrient food particles as is found in overfeeding. But let a leaf decay every once in a while, much is to be said about the bioavailability of macro and micro nutrients when various protists and bacteria have consumed their portions. Id say as the system ages somewhat, use a couple substrate boosts every now and then to charge up your heavily rooted anubias forest.
Just my .03,