You can't actually consolidate until you graduate and your loans are no longer listed as in-school. To be nice, your financial aid department may not report you as graduated until June--it may be worth talking to them about when they update the student loan clearinghouse. It can sometimes be a very small window where you only have a week or two to file, since if you wait until you start internship, you now have a salary (though per the poster above their co-interns did not update their salary information when applying for their repayment plans, but I would recommend against this, especially if you can do it the kosher way and apply for consolidation and REPAYE when you actually have $0 income.
As for taxes, definitely file. Also, keep track of any tuition you paid this year--if you didn't pay your spring tuition until after the new year, you can get a nice tax deduction/credit for next years taxes. Same goes for moving expenses--hold onto all those receipts!