Words with 'a' as the first letter that end with 'is'

What's an unusual word on this page of words that start with 'a' and end with 'is'?
You can choose many weird words on this page, with that said our favorite word happens to be 'agrostis'. The definition of 'agrostis' is as follows: "A genus of grasses, including species called in common language bent grass. Some of them, as redtop (Agrostis vulgaris), are valuable pasture grasses.".

In total, how many words is it possible to make using the combination specified?
There are 552 words that one can make using words that start with 'a' and end with 'is'.

How many characters does the biggest word from this list consist of?
The longest word one can construct from this list is 'acrotrophoneurosis', and it has 18 characters.

Is there any word on this page that sticks out as the most common?
'Amis' is the most well-known word from this page, ranked 7793^rd most common word.

In Scrabble, what's the best score you can get using this list of words with 'a' as the 1st letter that end with 'is'?
Considering the range of words to choose from, your best option is 'alfaquis' scoring 20 points overall.