What does this below rebus puzzle mean?

Which digit occurred maximum times between the number 1 and 1000?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Which alphabet letter is a question?

What is the longest word in the dictionary?

Can you find a seven digit number which describes itself. The first digit is the number of zeros in the number. The second digit is the number of ones in the number, etc. For example, in the number 21200, there are 2 zeros, 1 one, 2 twos, 0 threes and 0 fours.

Here is a conversation between a couple who both are software professionals.

Husband: Hey! What is your date of birth?
Wife Replied Angrily: It is 591062400
Husband after doing some calculations replied, "Got It".

What is the DOB of the wife?

When 99 is considered higher than 100?

What is the end of everything?

A Car is crossing a bridge 2 miles long. The bridge can only hold 10000 lbs, which is the exact weight of the car. The Car makes it half way across the bridge and stops. A bird lands on the car. Does the bridge collapse? Explain.