How many characters are in the largest word on this list?The biggest word you could construct from this list is 'polytetrafluoroethylene', and it consists 23 characters.
Is there a word from this page which might be considered as unique?The most interesting word from this list is 'pollinate'. It is defined as "Pollinose. To apply pollen to (a stigma). -- Pol`li*na"tion, n. (Bot.)".
How many words are possible to make using the combination specified?There are 566 words overall.
In Scrabble, what's the highest number of points possible using words that start with 'pol' and include 't'?Given there are a sizeable 566 entries, your best option is 'polytypy' which scores 21 points.
Is there a word on this page that stands out as the most popular?The most popular word for the combination you requested is 'political'.