The Head gasket blew probably at about 75K. I noticed oil spots on the driveway. I had heard about the gasket problem, but thought I was impervious. At about the same time, I have had a scenario where the throttle RPM's do not dive back to idle immediately when I step off the pedal about 2/3rd's of the time. I figured it was a "chip" or a vacuum leak and have asked the "5 Star" dealer twice to please fix, but they have been unable to duplicate it, they say. I also had a situation where the key would not turn the tumblers in the ignition at about 25K. This required a new tumbler to be installed.
I originally had a '95 baseline model which I put 80K on before trading for the R/T in 1999. I prefer the wider torque band of the SOHC 132Hp engine, but the acceleration of the DOHC at 40MPH onto an expressway is great. I recently bought a 2002 Neon SXT for my daughter. All three are manuals. For the most part, the three cars have been bulletproof. The rear seat area is enormous for a small car. With 83K, I have not required a brake job yet and I drive hard. The front disks were way over engineered for such a light car.
I may have some idea as to why it isn't returning to idle immediately. I have a 1997 highline coupe that does the same thing. I have found that it only does that when either the heater or a/c is on. I don't think it's a problem, just a quirk that the cars have. however, if it maintains more than 2000rpm when it happens, I would get it looked at, I suggest having them look at the heating and a/c system.
I currently own a 99 Dodge DOHC Neon 5 speed and I have also had most of the same problems, but whoever told you that it was your head gasket that blew and caused the leaking oil is not correct; a head gasket would be causing you to leak antifreeze. I also had the same problem with the oil, but it's supposedly a common problem with the DOHC models (an expensive one at that), but it's your front and rear main seals that will cause you to leak the oil. It was leaking on my belt on me and causing a god awful squeal from the oil eating the belt, so I replaced them... however I would like to say that I love the car; even though it can be a headache sometimes, it's fast for a Neon and gets excellent gas mileage and they will also take a pounding...