No one wants to have it, but if one got it, he does not want to lose it. What is It?

I am eight letters long - "12345678"
My 1234 is an atmospheric condition.
My 34567 supports a plant.
My 4567 is too appropriate.
My 45 is a friendly thank-you.
My 678 is a man's name.

What word am I?

What jumps when it walks and sits when it stands?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

A man and a dog were going down the street. The man rode, yet walked. What was the dog’s name?

If a wheel has 54 spokes, how many spaces are there between the spokes?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Two fathers and two sons went fishing one day. They were there the whole day and only caught 3 fish. One father said, that is enough for all of us, we will have one each. How can this be possible?

What kind of tree can you carry in your hand?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?