My daughter is in College with visa H-4 (Florida). She also was considered In State Student for tuitition purposes. The documents requested were: my husband's and my daughter's passports and I-94's (my husband has the H-1B), license driver, and another proof of residence in Florida proving that we live in Florida for the last 12 months. And that is pretty much it.
I can't tell you about the expiration of the I-94 but in our case, the registar took a look at all the documents and made copies of them.