-- If you do something right, will people know you've done anything at all?

No. Never. Unless by a later change in societal "norms" and politics, then it's made wrong.

-- If there is no heaven or heck, are we in purgatory?

Probably.

-- If a tree falls in the forest, and no-one's around to hear it, does it make a sound?

A better question is, if a tree falls in the forest, and it hits a mime, does anybody care?

-- If reincarnation exists, will we remember anything from a past life?

Ask the people in the Historical Figures wing at your local insane asylum.

-- If we spend our entire life without regret, will we die happy?

Depends on whether you mind working hard to achieve in life, only to get it in the shorts in the bitter end.

-- If we spend our entire life watching Futurama, does anybody care?

The "Television rots your brain" activists and the people running any Futurama fansites in need of episode guides will.

That second answer's a Far Side cartoon.

-- If you do something right, will people know you've done anything at all?

No. People expect you to do things right.

-- If there is no heaven or heck, are we in purgatory?

Maybe.

-- If a tree falls in the forest, and no-one's around to hear it, does it make a sound?

No. Existence needs confirmation. Without anybody to confirm the sound, it doesn't exist.

-- If reincarnation exists, will we remember anything from a past life?

No. What's the point of reincarnation if you inherit painful memories that came from a long time ago?

-- If we spend our entire life without regret, will we die happy?

No. Without regrets, happiness doesn't exist.

-- If we spend our entire life watching Futurama, does anybody care?

Probably not.

No. Without regrets, happiness doesn't exist.

Wow. I guess I never thought about it that way.

That's weird.

-- If you do something right, will people know you've done anything at all?

The Term 'Right' describes a concept which couldn't possibly exist. The same goes for 'Wrong'. So it doesn't matter.

-- If there is no heaven or heck, are we in purgatory?

Prove that where we are even exists.

-- If a tree falls in the forest, and no-one's around to hear it, does it make a sound?

Moreover, how do we know it fell? How do we know it didn't just come to life, lying sideways in the dirt?

-- If reincarnation exists, will we remember anything from a past life?

Apparently, this only happens if in a past life you were someone that your current life knows so much about.

-- If we spend our entire life without regret, will we die happy?

Theoretically, yes. I have yet to find a willing volunteer.

-- If we spend our entire life watching Futurama, does anybody care?

Only those who make money from our doing so. Everyone else couldn't give a monkey's.

-- Depends, did you do it right for yourself or someone else

-- That is what we dont know. Live the best of your life while you still have it, because who knows what lies ahead.

-- It's either yes or no

-- Reincarnation doesn't exist.

-- No, we as humans strive for perfection if everything is perfect what can we strive for? what have you accomplished.

-- Perhaps but only you should care. What would you think when you died if yu spent your whole life watching TV.