Okay dude, THat crunchy feel is probably because of two things:
1) the cable needs to be lubricated. there is a special tool that allows you to shoot grease into the cable sleeve with the cable still installed. this may fix your problem altogether, and the dealership can do it for you, or, you can get the tool from an auto parts shop and do it yourself (you'll also need a grease gun & some lithium grease)... unless of course...
2) your throttle cable is beginning to fray, or come unraveled somewhere, in which case, you should replace the entire throttle calbe.
Other areas to check out would be the throttle rotator on the throttle body (the little "half-moon" shaped wheel your throttle cable goes to), it may be bent a little, or, the springs on the rotator may be cracking. also be sure to inspect the ends of the cable. both at the pedal & TB. make sure it's all in good health.
You may want to clean your Intake
manifols and throttle body with throttle body & MAF cleaner spray (STP and others make this, available at auto parts stores) this will clean out carbon sludge, and you may restore some of that power, clean the MAF while you're at it; be sure to read the instructions for use on the can, it's real important. that may also be why the throttle is hard to manipulate; if the TB butterfly is all gummed up, cleaning it may help.
Odds are, you just need to clean up the Intake
tract a bit, and lube the throttle cable.
BTW: one more thing... This may sound stupid, but honestly, this happened to me, and you'll slap yourself if it happens to you too.
I recently put an additional set of plasticolor mats in my GTS, to keep from wrecking the factory mats at the car wash, or when wrencing on it. I use them daily to keep my interior clean.
I noticed the car wouldn't accelerate as fast as it used to, and the lift didn't engage as easily.
I was able to get up to 100 on the interstate, but from there, the car just crawled. I couldn't figure it out for the life of me, then it hit me... My new floormats were taller than the stock ones, and the accelerator pedal, well, it has almost no clearance between the floorboard and the bottom of the pedal when it's floored. my new mat was geting in the way of the pedal's full travel (the mat is only like 1/2" thick).
I slid the mat back, and under the front seat a little, so the top of the mat was level with the factory mat (notice, it's cut out by the gas pedal?). suprise, suprise, it fixed the problem.
Sometimes the solution is so simple, you fail to realize it immediately.