It’s hard to explain… Do they have a term that means “overblown crud” in your native land? That’s a good place to start…
If I translate it correctly, I think it comes out “type A personality with undeserved credentials, too few useful tentacles, and methane-infused breath.” That about right?
Artist’s block? Heard about it. You could stick with the theme of half-seas and make a band? No wait. Give your centauris an instrument too so they can only play at the shore! Add a squiddy for multiple instruments. Now THAT is a band I’d pay to see play.