That's up to you. Membership in a Greek organizations is a commitment, but you are a student first at Denison. You need to decide how active you want to be. You'll have company in most sororities and many fraternities. The spotlight on alcohol-related issues of health, safety, and liability has fostered programs to reduce abuse.
Most members think so because so much opportunity is built in.
And that goes beyond parties to include such activities as intramural, alumni events, conventions, and weekend getaways. The elitism issue is probably a throwback to days when there were fewer choices. As to conformity, you can make that call during Rush. If all members dress and sound alike, draw your own conclusion. Yes, in several important ways.