Noisy - of course, it's noisy. It is a character meal, with lots of young kids, that occasionally involves everybody swinging a napkin over their heads to music. Some might actual refer to this as fun. There is probably no other restaurant on property where you'll see kids having as much fun as at Chef Mickey's.
Crowded - it's one of the most popular restaurants at WDW....but never more crowded that the capacity that their tables allow. We've been there a few times (not in the last five years, to be fair), and we never felt like it was so crowded that we couldn't get food reasonably quickly and back to our table.
Food Quality - it's a mainstream, Disney buffet with no particular theme. As long as it's decent, that's all we can really hope for, and "decent" is a pretty good description. Not great, but not horrible.
Chef Mickey's is a rite of passage for anyone going to Disney World. You can watch the monorail go through the hotel while you eat...to a kid (and lots of adults), that's pretty dang neato. Check it out with the attitude that it's going to be fun, but with the realization that it won't be the best meal you have while there (at least from a food standpoint). Going to certain restaurants at WDW is all about having the proper expectations going in.
As for fireworks, while you can't see them from the restaurant, there is a deck on the 4th floor of the Contemporary (somebody correct me if I'm wrong) that allows for fireworks viewing, so if you can't (or don't want to) get back to the MK, there is still somewhere to watch.