Don't panic. A CE code rarely means "this part is bad"....so don't start swinging a baseball in a dark room, by replacing sensors. If you have already done that...and the problems still exist, then its probably not a sensor. Code chasing and trouble-shooting requires an almost Dr. Spock-ish logic. Human nature tends to make us think the worst but, most often...its something really simple. So for that reason...always start with the easy (cheap) stuff.
First...realize you have multiple codes. Spock says..."its very rare that multiple sensors would fail at the same time". That can make things more difficult but, it can also mean that something is causing many sensors to freak-out, instead of just one. The most common cause of this is erratic or low voltage...often traced to bad battery terminals or stray coil voltage. Make sure the cables are good & tight, especially the ground (the black one). H3's are know to have crappy cables.
Next...realize your codes are all mis-fire related. Some are random misfires, and also a crankshaft sensor. If it were just the crankshaft sensor by itself...I would check that sensor. But, since you've got all kinds of stuff goin on...I tend to think its something else. The first thing I would check is the coil-packs on top of the motor. Spock says..."electricity follows the path of least resistance". When the electrical current can't jump the spark plug gap inside the cylinder...it will usually jump thru the insulation and ground out on the nearest metallic object. This is VERY common problem on the L5 motors...and its especially common on the H3 because the plastic louver on the hood snaps in to holes that are perfectly placed (yup)...to funnel rain water right down into the #1 plug well. This will cause the voltage to jump from the coil to someplace its not wanted...and that will play hell with a computer controlled motor. IF YOU NOTICE THE STUMBLING GETS WORSE WHEN ITS RAINING OR DAMP OUTSIDE...that should tip you off that it might be stray voltage.
If the battery terminal check doesn't yield any results...take the air box off the top of the motor and remove the coil packs. This is a simple procedure, and you need to pull them up off the valve cover and see if there is a bunch of nasty rust flakes and wetness down inside the spark-plug wells. If so...that's your purp! Clean em up and re-install them...see if it makes a difference. GM recommends replacing them because once they leak voltage, they tend to create a "hot-spot" in the insulation, and even if you clean them...the electrical path has been established, and it won't be long before they start shorting out again. But you should be able to notice a difference by cleaning them and going for a test drive. Its a cheap and easy way to eliminate one more possible cause. My money is on the coil packs/spark plug boots.
The H3 will set specific mis-fire codes for each cylinder. You can use this to trouble-shoot by swapping the suspected coil (lets say #1) for...the #4 coil. Then drive it a few days and see if it throws a mis-fire code on the #4 cylinder. That will tell you without question that the coil is failing and it needs replaced. Also...the failure rate on these coils is very consistent. If one is going...there will usually be more to follow shortly. GM almost always replaces the entire set of five for this reason.
The K&N is fine...thats b.s.
Sludge effects the crank sensor?...that's really reaching. I don't buy it.
Drive long and prosper.
