well its pretty damn hard or impossible to do most rollerblade grinds, some are possible like crossing your skis, but seriously that is gay, its like when people do mutes on a 20 foot straight air.
the broken grinds look pretty cool, but they can also look dumb, in a couple years i bet we will have them down, i like the ones where you have both skis on the back edge, that can look cool.
and if you are trying to copy another sports grinds how is that progression? its just copying.
snowboard grinds are more possible than rollerblading grinds, nose/tail presses, stuff like pollards nosepress where he is going straight, like riding the box straight or switch and doing a nose or tail press, nobody does those and they could definatly look cool. or like how jf houle( i think) does little ovecrook looking grinds.
so dont limit it to rollerblade tricks i dont have a problem with some, but remember we are on boards not shoes, so it makes more sense to do snowboard type grinds cause so many more grinds are possible that way.