I am extremely tiny -- short and petite -- and I want to try wearing those saggy butt harem trouser things. Is that a bad idea?
Not at all! Harem pants and drop-crotch trousers can seem scary, but once you find the right level of slouch for you, it's smooth sailing to comfort. I think ones that are a little loose around the leg and have a crotch that doesn't drop past your lower thighs are the easiest ones to wear and won't swallow your lower body in saggy fabric.
My trick to wearing harem pants is to think of them as regular pants and pair them with everyday pieces that are a bit more streamlined, like a soft t-shirt and a blazer or a fitted sweater. Think of it as mullet dressing -- you might be having a total party with excess fabric down below, but up top, it's business as usual.