If you aren't designing a card directly, and are just suggesting mechanics, then this goes in the Design Theory section of the Card Ideas and Art forum.
On-topic: Hand or deck destruction is a no-no among elementals. Dune Scorpion took quite a blow to the gut to get where it is now. Forced discards are fairly easy to come by, now that Silence is an existing card. Also, Nightmare and other things are good strategies if you want to directly control what creatures your opponent puts out.
Destroying all copies of a target permanent is like an Earthquake on roids. In other words, making the card will be difficult. It's pretty much an absolute pillar denial, meaning a Fire Lance or a Dissipation Shield mono would be rendered useless.
Your light shield is waaaaay overpriced. 6
just for something that unburrows another creature? Why would I want that? That pretty much doubles the attacking creature's strength. As of right now, the only things that can burrow are Devourers, shriekers, graboids, antlions, and mutants. Setting up a shield that only works on those guys is pointless.
The ability to heal every time your opponent draws a card is terribly hard to balance. To begin with, fighting someone whose deck is based on Hourglasses or Mindgates would make those decks drop in usefulness.