Kit Shelf Life

Ive been out of the brewing game for about a year due to a military deployment. I have a kit for an Autumn Amber Ale that I got before I left, besides new yeast what of the other ingredients (malt extract, grains, hops) are a must for replacement and what are "good ideas" to replace.

Separate question: when doing a full boil you start with roughly 7 gallons right? cause it boils off to about 5? stupid question i know, but i just can't remember.

Thanks for all your help.