Is there an example word from this page which could be thought of as unique?The most peculiar word from this page is certainly 'polypifera'. The definition of 'polypifera' is as follows: "The Anthozoa.".
What's the most common word for this page?A popular word for the combination you requested is 'opera'.
Which word on this page has the highest character count?The biggest word that's possible to assemble from this list is 'palaeodictyoptera', and it is made up of 17 characters.
How many words are possible to make using the combination requested?You'll find 511 words overall.
In Scrabble, what's the most points you can get using this list of words containing 'o' and ending with 'ra'?Since there are plenty of words to choose from, your best choice is to go for 'nonzebra' scoring 19 points overall.