Get a fine diamond stone (600-1200 grit). Use it to keep your edges free of burrs. The gummy stone is good to finish off the edge and get to baby butt smooth. Make sure you get a hard one, it's a carbide impregnated material that feels like an eraser. I do this every evening and it only takes a minute. As long as you don't get the cheap "economy ones", they'll last you years. $25 well spent.
If you need to tune the edge, do it prior to deburring as described above. The tuning tool you linked is fine for all style sidecuts (regular blended multi-radii cuts, magnetraction, Salomon Equalizer, Griptech etc.), but I'd only use it on the side edge. A base edge guide should be used for the base edge. Depending on the conditions you ride (hardpack dulls it faster) preference and style, you might tune every night or might only tune once ever 3 or 4 days or even more. I rarely tune my boards because I prefer it for riding in the park and buttering on boilerplate. With all these new sidecut technologies, tuning is becoming less and less critical as far as freestyle goes.