Words that contain 'ps' and end in 'in'

What's an interesting word from all the combinations possible on this list?
The most notable word based on a recent poll is 'capsicin'. The dictionary defines it as "A red liquid or soft resin extracted from various species of capsicum.".

How many characters does the largest word from this list contain?
The word 'bacteriorhodopsin' contains 17 characters.

What is the most common word that has 'ps' in and ends with 'in' in the dictionary?
As far as well-known words go, there's 'sheepskin', which ranks as the 38988^th most common word.

What is the highest scoring word you can play in Scrabble ?
It is possible to make 'kipskin' which gets 17 in Scrabble.

What's the total number of words one is able to put together using this combination of letters?
You can pick from up to a maximum of 43 entries.