In total, how many words are there using these particular combinations of letters?One can derive 26 words using the combination you specified.
How many characters does the longest word on this list contain?The word 'erythrocytorrhexis' contains 18 characters.
What's a peculiar word from the word combos possible on this page?The most notable word in our opinion is 'erythrophyll'. The popular definition of 'erythrophyll' is as follows: "The red coloring matter of leaves, fruits, flowers, etc., in distinction from chlorophyll.". Source Cambridge Dictionary.