My personal opinion would be that insurance is valid for as long as you pay the premium and own the phone. Insurance and warranty are two separate things.
Also, although its always recommended to flash stock software, for a hardware damage claim, it shouldn't matter one bit what software is running as its irrelevant to the claim.
Also, although its always recommended to flash stock software, for a hardware damage claim, it shouldn't matter one bit what software is running as its irrelevant to the claim.