On the rattle, Does your jeep have skid plates? Check to make sure all of the bolts are still in. I had a bolt come out and cause a rattle in the front passenger side of the jeep. I also had a rattle when a rock got stuck above the skid plate. Don't know if that is your problem but it worth a look.
On the brakes, I would take it to a shop like Midas and ask them to give you an estimate on fixing the problem. They will take it for a test drive and tell you what is most likely wrong. After you get an estimate, you can decide whether to have them fix it or do it yourself.
On the rythmn thing, Sorry, I never could get the rythmn thing right