Power steering leak and t-case noise

OK, so I had my oil changed yesterday and they confirmed that I have a really bad power steering leak. The guy who looked at it thinks it's from a vacuum hose that's busted. This has been going on since I got a new p/s unit installed by tarheel 4wd back in november of last year. What do these things typically run? I'm gonna take it over to tarheel asap b/c they need to fix it since they were the ones who installed the new p/s unit.

Second thing is, I've noticed a low rumbling/vibrating noise that appears to be coming from my transfer case. I can hear it right under the shift lever from inside the car. I only notice it at idle and not at speed, but it bothers me enough to ask on here. Is it anything to worry about?

Lastly, I'll admit I'm a bit rough on my Jeep when it comes to cold starts and driving it immediately. Usually I'm running late for class, so I'll start it up in the mornings and immediately put it in reverse to back out of the driveway. However, it sometimes won't want to go, ie, when I press the gas pedal, it almost has the opposite of the intended effect, it's like it shuts off the gas going to the engine or something. This used to happen to me when I'd give it a fair amount of gas when doing u-turns, it's like something cuts off but no one has ever been able to identify what the problem is b/c I can't replicate it. Anyone have any ideas of what it is and why it's happening? Is it just that it hates cold starts? It's got relatively low miles for a 10-year-old XJ (98k) so I'm thinking that shouldn't be playing a part.

Dang holiday weekends!

As for the "vacuum hose" on your ps, I think they meant low pressure or return side hose. I wouldn't be in to big of a hurry to blame the shop, hoses can let go at any time for a number of reasons. If it was leaking right after they did the job you would have had some leverage if you went back within a week of them doing the job.

You don't say what transmission you have, but any vehicle is likely to stumble upon a quick cold start and go situation. Try giving it a full minute to run and see what happens.