The “-go-” part in Ergomania should remind you of someone who is always raring to go, someone who cannot sit still at one place but keep on going, keep on moving forward.
“Oniomania” should remind you of someone who is obsessed with owning things.
“Megalomaniac” should remind you of Megawatt and watt is the S.I. unit of Power. Thus, megawatt refers to mega power.
Livery rhymes with shivery. When one is shivery, it is apparent from their outward condition. Similarly, livery tells us about the rank and status of the person clad in that.
You write quotes in your diary daily. This quotidian habit of yours helps you memorize quotes.
You are anxious that there is a trap just ahead of you. Hence, the feeling of trepidation!
“Consternation” should remind you of “Concern”.