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

What's the highest possible score you can get in Scrabble from this list of words containing 'a' and ending with 'ncy'?
As there are an extensive 553 entries, it's best to go for 'piquancy' which scores 24 points overall.

Is there a word on this page that sticks out as the most common?
Rating as the 1477^th most common word, you will want to ensure you have 'fancy' in your arsenal.

In total, how many words are available using the combination requested?
On this page of words that contain 'a' and end in 'ncy', there are 553 effective entries which are possible.

How many letters are in the longest word from this list?
'counternecromancy' (17 letters)

Is there a word from this page of word that has 'a' in and ends with 'ncy' which could be deemed as interesting?
One example of an unusual word from this list is 'aberrancy'. According to the Oxford dictionary, 'aberrancy' means "State of being aberrant; a wandering from the right way; deviation from truth, rectitude, etc. Aberrancy of curvature (Geom.), the deviation of a curve from a circular form.".