Some cases of so called memories from past lives have shown to be hoaxes, while others have yet to be substantiated by sufficient evidence to warrant belief. I want my beliefs to be reasonable, in accordance with reality, so I abstain from believing any extraordinary claims until evidence is presented that stands the test of rigorous skepticism.
I don't believe there's an "after death" period of time from one's own subjective perspective, because it hasn't shown to be the case. Therefore the second question seems to assume an invalid premise.
Conscious awareness has been demonstrated to be a function of the brains of animals that are able to plan ahead, remember past events and so on.
At the time of death, at the point of losing consciousness, the qualia of the self simply ceases to exist. There is no you, me, them. No delusion of individuality, and none of the problems it has caused all of us. The neural function responsible for creating the illusion that "I am me" is defunct from that point on.
Everyone has already experienced what it's like to not exist, for billions of years. Time and space is simply skipped on a massive scale, without the delusion of the self, just as it should be in my opinion.
There is no better heaven you can ask for than the liberating, protecting, truthful nest of absolute nothingness. All of us are bound to attain it, and there will be no us when we do.
I'm prepared to answer any follow-up questions.