I'm having a hard time understanding how と works with negative verbs. With positive verbs, it is easy to see the timeframe of いい because it occurs after the verb happens, but if the verb ends in ない, how do I know when いい happens when a verb ending in ない means nothing occurs? I only seem to have this problem with いい and not だめ. For example, 食べないとダメ means that if you don't eat, you will eventually have something bad to happen. If reworded as 食べないとだめになる, the sentence still makes sense because the original sentence also reflected a change in state. However, in a sentence like 電池が爆発しないといい, 爆発しないとよくなる seems to have a different meaning.
First of all, "食べないとダメ" means "you have to eat," not meaning "食べないとだめになる."
In this topic's context, "いい" is used when you describe your hope or wish. For example, "爆発しないといいな" means "I hope it won't explode."
yes, the sense is different:
-爆発しないといい you express your hope, you hope that it won't happen
-爆発しないとよくなる doesn't make much sense with this verb, but you simply state that something good will come out of not doing an action. There is no notion of hope