Interestingly, these words are all fairly familiar to me, save "parvenu." Some of them even made my own list of favorites!
A brilliant set of complex words that could be used in writing!!
I just used some of these and then some at sixwordstories.net.
Here's what I wrote:-
1) She sat there, while I masticated.
2) The siren's voice was mellifluous, hypnotising.
3) Beslobbered, vexed, I opened my portmanteau.
4) Erudite and loquacious, he elucidated.
I'll agree with all but Portmanteau, and not that I'm at all anti-semetic, but Foible reminds me of yiddish, and while not a bad thing as such, it almost compartmentalizes it in my mind to the point that it becomes inherent to the personality, whether it be a caricature in conversation or the imagination or envisioning when reading.
Nonplussed is too pretentious as far as I'm concerned, like something a hipster playing the part of an erudite might say.
Parvenu is beautiful, and if paired appropriately, would be a fitting companion to Nouveau Riche.
Mellifluous stinks of fantabulousness though.