Material information is that information which enables the insurers to decide: Whether they will accept the risk? If so, at what rate of premium and subject to what terms and conditions?
Facts such as Measures implemented to reduce the risk, Facts which the insured does not know or is unaware of, Matters of law etc need not be disclosed
Once the policy is accepted, there is no further need to disclose any material facts that may come up during the term of the policy.
Insurable interest refers to Financial interest of the person in the asset to be insured. It makes an insurance contract valid and enforceable under the law.