Im currently stationed in KS where exhaust laws are very limited, i wanted to unbolt the X and have fun one of these days but ive heard of burning valves because of backpressure, anyone have any experience with this?
Bad idea. Might be ok on a carb mod with long tubes but your likely to cause major issue. Won't work on a fuel injected car unless you have an aftermaket puter and able to tune w/o the use of the o2's sensors.
Keep the exhaust, use free flowing mufflers and no cats. Your car and our ears will like you for it.
I'm not sure what you are talking about exhaust laws being very strict in Kansas. Maybe in certain cities, the local police will be unhappy (Olathe), but generally it isn't a big deal if your car is a bit loud. I've driven my 88 turbo with an open downpipe quite a bit (though it is quieter than an NA car would be).
Running open headers probably isn't a great idea. The problem is not specifically burning valves... it is cold air reaching the exhaust valve after you've turned the engine off, hence probably not a good idea with a shorty, but no problem with a turbo or long tube header. Personally, I'd HIGHLY recommend AGAINST running an open exhaust. At least run a cat or single muffler to quiet it down a bit, because a completely open exhaust will truely hurt your ears after a short driving distance, especially if it ends underneath the car. Besides, the exhaust system doesn't cost you much power. Get an offroad pipe and the total system will only rob a little bit of power, even running the stock mufflers.
I guess if you just want to have fun for the day, at least keep the X on and remove the mufflers. That will keep the hot exhaust gases from blowing on something important, like the frame. Metal properties can and do change from heat exposure.