This can let you cascade from cards you cascaded into

Indeed. It's a really neat idea I think can add a lot to a deck built for it but at the same time...3/1. That's an ooferino with extra oof

Is toughness based removal common in edh?

1 toughness can be killed en passant by a lot of things

It is easily killed. But it's also going to be the ramp deck (which means it will also most likely cascade into a ramp spell each time you cast it), so you can probably afford to cast it again.