1.) The whole sesquipedalian thing is just a joke. I like how the word sounds. Though, I do live in a rural section of the U.S., and, around the geniuses (and I use that word loosely) that live here, I am a sesquipedalian. Trust me, though, compared to any of you, I'm merely literate.
2.) I need to clear something up here. Tautology is, basically, using two synonyms in conjuction with each other (i.e., fear and trepidation). But pleonasm is using two synonyms (i.e., the man he said) when using one will suffice, but using the other in the same sentence is wrong.
Good lord, I hope that made sense. If not, please correct me.