Of course! Not only can you do that but you could eat the same meal every day. Last year we had three breakfasts at the Crystal Palace. Disney doens't care. Where they could get you is if you book two dinners on the same night. They assume that you can't be eating in two places at the same time and they are liable to drop one of them. Hope that makes sense. Enjoy Chef Mickeys!
Absolutely, just like you could make reservations for a restaurant in your hometown for a couple of days in the same week. Disney's no different, they're delighted to have you in their restaurants as often as you'd like to go.
The one thing they won't let you do with dining reservations - and maybe you've heard this, and were thinking of it - is to make reservations at multiple restaurants for the same date and time, only intending to use one of the reservations. Some people can't or won't make a decision on where they're going to dine, so they'll make reservations at two or more restaurants for the same time, just to hold the tables. Disney will often cancel one (or all) of the duplicate reservations.
Hey, we always begin each trip with dinner at Chef Mickey's also!!! We have ADR's at 'Ohana for dinner on two different nights during our upcoming June trip and I can't wait!!!