I agree with the posts above: MAF, MAF, MAF. It's common & explains all the problems you listed.
http://www.benzworld.org/forums/w163...placement.html
Probably wouldn't hurt to pour a can of injector cleaner in the ole gas tank just to make sure it's not a dirty injector. It's cheap compared to a sensor replacement & it's worth a shot!
The alternator racket is probably bearing related. The best way to tell (& this has been mentioned here before) is to take a long handled screwdriver & place it on the alternator body while the car is running. The screwdriver acts like a stethoscope, you'll be able to hear every squeak & rattle. Place the handle of the screwdriver in your ear & make darn sure you don't have anything loose fitting that can get caught in anything!!! If the alternator sounds reasonably quiet then the noise is coming from somewhere else.