I clean and wax mine about monthly. I use the Maguires clean and wax or any other reputable brand, the kind you put into a bucket of water and wipe on with a clean rag, rinse with hose, then Dry off with a nice terry towel. Looks great and doesn't take but 30 minutes. I do the Maguires Tire shine too, looks great.
I have never clay barred, but probably should. Take care of your Jeep and it will take care of you.
As often as you are willing, but by auto detailing standards, no less than twice a year.
I use a liquid wax every few months, but wash and use a detailer spray (sealant, PS BeadMaker) every 2-3 weeks. The paint stays slick as ice, and I've had multiple people ask me if It's been ceramic coated, which I answer no.