Does freezing food preserve it past its expiration date?

yes, but according to Good House Keeping there are a couple of items you shouldn't freeze like:

Salad greens and crisp raw vegetables to be used in salads and sandwiches, Eggs, Creamed cottage cheese, Sour cream, Heavy or whipping cream, Potatoes

long frozen food stay good expiration date

You can freeze on last day of sell by/ use by date.

Then when you de-frost overnight you cook on the day after.

Yes.

Yes as long as it is fresh when frozen

yes

if in doubt through it out