If you want to be safe, there is glue specifically marketed for tanks. If you do glue moss, go crazy with it because it grows slooowww unless it's java moss. But yeah, your substrate is limiting you to larger plants with thicker roots, unlike say a dwarf baby tear which would be almost impossible in the gravel.
As for ferts, go to rotala butterfly and check out their dosing calculators. You need nitrate, potassium and phosphate at a roughly 10:10:1 ppm ratio. Then you need calcium and magnesium at a 3:1 ratio (can be lenient here) from gh boosters if you are using RO water. Then you need iron and micros, which CSM + B usually gives you easily.