Yes, good idea on the laminate caulk at the back splash area. We're not having much issue with the back area as much as around the faucet. That's where it's leaking on our unit. I tried some other type of caulk there, but it didn't work very well. I'll try the the kind that you mentioned.
I'm not sure about the weight of Corian; Haven't done any research at this point. If the caulk works, I'm gonna stick with what I've got.
Cheers!