Please don't cook in your room unless you are staying in a DVC resort that has either a full kitchen or a kitchenette.
#1 for this time of year: Stay onsite so you can get into the park. If you stay offsite, and the parks close, you aren't guaranteed any entry. If you stay onsite, you are at least given the opportunity to go to one park. Also, if you stay onsite, you can go to at least one park 1 hour early everyday for Extra Magic Hour. Further, if you stay onsite, you can leave the park when it gets too crowded and go back to your resort for a swim.
Go to the park you want to be at early. If you wait too long in the AM, you may be shut out from that park until later in the afternoon or evening.
Eat a large, late breakfast and early dinner. Then you can skip lunch.