What should come next in the following letter sequence?

A A B A B C A B C D A B C D E A B C D

If the first and second letters in the word 'MISFORTUNE' were interchanged, also the third and the fourth letters, the fifth and the sixth letters and so on, which letter would then be the eighth letter counting to your left ?

How many pairs of letters in the word 'CHAIRS' have as many letters between them in the word as in the alphabet? 

From the word 'LAPAROSCOPY' how many independent meaningful words can be made without changing the order of the letters and using each letter only once ? 

From the word 'ASTOUNDER', how many independent words can be made with-out changing the order of the letters and using each letter only once ? 

How many independent words can 'HEARTLESS' be divided into without changing the order of the letters and using each letter only once ?  

Two letters in the word 'LEMON' have as many letters between them in the word as in the alphabet Which one of the two letters comes earlier in the alphabet ? 

If in the word 'DISTURBANCE', the first letter is interchanged with the last letter, the second letter is interchanged with the tenth letter and so on, which letter would come after the letter T in the newly formed word ?

Which letter in the word SELFRIGHTEOUSNESS' does not change its position when the letters are reversed ?