S.W.
I would always file a 1040 to be sure I was getting the largest deduction possible. It really isn't that hard...
Yes, we are supposed to keep receipts for seven years. The reason is in case you are audited. If you can reproduce all the data used to file your taxes for seven years back, then you can respond to an audit. I'm not sure if it matters if this data is kept on paper or available from online sources (I don't receive online statements for anything, all transactions are handled online). You may need to talk with a professional tax person about that.