Kassadin and Wave Clear?

Wave clearing, especially early (though the problem never REALLY goes away), is very difficult for Kassadin. Honestly, if you really want to shove a wave, just don't be afraid to Riftwalk directly on top of it. I find that you can clear a lot of minion health with R-E-R, maybe even kill the caster minions. As for wave clears when there's a champion nearby...well, that's what turrets are for.