Words that contain 'a' and end in 'ff'

What is the highest scoring word you can play in Scrabble ?
With an enormous 121 entries, you may want to opt for 'outquaff' which scores 23 points in total.

What is an unique word from this list?
The most strange word in this list is 'distaff'. It is defined as "1. The staff for holding a bunch of flax, tow, or wool, from which the thread is drawn in spinning by hand. I will the distaff hold; come thou and spin. Fairfax. 2. Used as a symbol of the holder of a distaff; hence, a woman; women, collectively. His crown...".

What's the most popular word that has 'a' in and ends with 'ff'?
As far as popular words go, there's 'staff' which is the 3323^rd most common word.

In total, how many possible words can you make using the combination specified?
There are up to 121 entries that cover all combinations.

How many letters does the longest word from this list contain?
The largest word is 12 letters long, which is 'quarterstaff'.