How big of a commitment is it? (will I be able to do other clubs too?)

You might be able to manage one other club, or an extra class. Think of rushing/pledging as an extra class. It's a time commitment, but if you're good at juggling your time then you'll be alright.

What is the living situation typically like for each year?

Whatever you want it to be. Want to live in the dorms? Live on campus. Want an apartment by yourself? Do that. Want to live at the frat house? There's probably room on the lease. Want to live with one or two brothers? You can get a place together. You have more options than people that aren't in a frat/club, but you have no obligations.

What events do fraternities participate in besides parties?

If you're in a national fraternity, then philantropy is generally pretty highly valued. Fund raisers, charity events (relay for life, polar bear plunge, etc.), and community service (volunteer hours at a vet, trash pickup, etc.) are common. They may also participate on on-campus events like Greek Week competitions, plays, awareness events, etc.

If you're in an off-campus fraternity (not nationally/campus recognized) then it's mostly just parties and socials. You won't find many charity/community events there.

Does joining a fraternity significantly improve party options?

Yes, for several reasons. Of course you get free access to your own parties, but Greek Life is also social, so it's easier to find parties hosted by others. It also opens up the door for socials with other fraternities or sororities, which are usually one-on-one (or or three-way, or four-way) private events. Think of it like a private party, Greek Life only.

How selective are they?

It varies. My organization vetos about 50% of the interested members and gives bids to the remaining 50%. Other groups may be more or less selective. Chances are if you really click with the guys you're rushing with, and you talk to them a few times, you'll get a bid.

Are the hazing stories true?

Some of them are real. Some of them are just there to fuck with you. And some fraternities don't haze at all. Every fraternity has their own policies. Mine hazed.

Is it hard to focus on school while living in a frat house?

I never lived at the house so I can't answer this.