The answers to these 2 questions subject to the Hell and Heaven's definition. Let's look the definitions of hell and heaven that I get from a dictionary:

Hell's Definition

• The world of the dead where you're being punished and suffer.

My take: A place of the dead? Hmm... why must be a place of the dead? To me a hell is simply a suffering condition and not really a place technically. This means it doesn't matter where you're, as long as you're in suffering, you're in hell. If we have to find a place to define hell, earth is the best place because most of us are suffering in some ways or another. Too bad, you are already in hell! :) lol

Heaven's Definition

• A place beyond the sky with great happiness, delight, or pleasure

My take: A place beyond the sky? Why must beyond the sky? It is not necessary and it could be anywhere. Just like hell, a heaven is not place but is a condition that make you feel like a place. Great happiness, delight and pleasure, where you can get those? It is all within you. If we have to find a place to define heaven, sorry no one has the answer. Some religions called this place a "Nirvana" but it merely another definition like "Heaven".

So, do hell and heaven exist?

Yes but not necessary the hell or heaven is a place, it could be just a condition.

By the way, when you're Hell doesn't mean you will be forever in Hell. Same to when you're in Heaven, will you be forever in Heaven? No, the suffer and happiness will end and restart. When the suffer restarts, it could be no longer suffer. When the happiness restarts, it could be no longer happiness. Everything is looping, remember?

P/S: After death, we move to another milestone but it is not necessary a hell or heaven. It could be something else and it doesn't really matter because it is merely just another milestones. 

Different religions have different answer to such question or perhaps different free thinkers have different answers for that questions as well. What really confuse you now is "If everyone has a different answers, how could all religions are the right one?" Interesting isn't it? But I will cover that next after I answer this question from my free thinking perspective. Let's see how I answer this question.

In order to answer this question, I need to recap of my previous posts or articles. Let's do a recap here. The first thing you want to know about death is life. What is life? Life by majority of definition is "Anything That Can Breathe". When the life is stop breathing, it is called "Death". Is this your death definition? If yes, you can read on. If no, this article doesn't answer that. You need to let me know what is your definition of death then so that I can give you a better explanation.

In fact strictly speaking, there is no death at all especially if you look beyond human's perspective. This is because life is anything that can move by its own and it is always in progress state. So, there is no death at all. However, if your death here is meant by human death, then that is called milestone in the entire system. So after this milestone, where do you go? This answers what happens after death...

"After Death, You Move On to Another Milestone"

So now this "Another Milestone" is the thing to argue here because that is where the religions out there define their own "Another Milestone". So what is this exactly the "Another Milestone"? What is the truth? Well, if all religions are right, what do you think is the answer? Yes, all milestones are right one too. There is nothing to argue about. The most important that you want to understand is after death, you're basically moving to another milestone. We can discuss more about this "another milestone" in the next topic especially you do not satisfy with this answer. :)

P/S: Disagree with me? I love your disagreement and I appreciate you can also comment here to share your thought. :)