Deep frying corn kernels starts busting/exploding in oil
It sounds to me like you are accidentally making popcorn, which is a result of hot gasses building up inside the hull of the kernel. Fresh kernels typically have a tougher hull than frozen or canned, both of which use methods that weaken the hull. Freezing the corn causes growing ice crystals to damage cells. Canned corn is boiled, which both seals the can and cooks the corn, softening it.
Here's some things you can do to fix your problems:
Boil the corn
Boiling would solve your popping problem, as the pre-cooked corn's hull would be soft, enough to release the moisture from inside, or only just split rather than have the entire kernel pop. It would also fix the issue with the cornstarch not adhering to the kernels, as the softer (and now wet) corn would be more prone to releasing it's inner moisture.

Boil the fresh corn for 3 - 4 minutes or until soft
Transfer corn into a colander or a sieve to remove excess water. Excess water might cause the cornstarch to clump together.

Freeze the corn
Freezing the corn beforehand would also soften it, just make sure to fully defrost and drain the corn (see above).
Fry the corn on a lower temperature
Your oil might just be too hot, causing the higher moisture inside to cook and expand faster than the husk, which could cause popping.