^ If you just got them, don't worry about them yet.
I wear mine just about every day, granted I'm usually walking around campus, and sitting down on dirty seats and benches. Just wear them regularly with your daily routine.
If they end up smelling from ball sweat after a month, then WASH THEM. If they don't smell, let them be.
I do not think dry cleaning is worth it. Waste of money. Honestly, if they smell, a little soak and agitation in cold water once ever couple months won't hurt them. The sky won't fall, gravity won't reverse...
Yes, hemming Weird Guys (tapered) makes the leg opening wider.