I personally contacted the Command via telephone in June of this year. The address they gave me for obtaining IDPF's was:
U.S.Total Army Personnel Command ATTN: TAPC-PAO (FOIA) 200 Stovall Street Alexandria, VA 22332-0404
If you want to verify this, the phone number where I reached them is (703) 325-4053.
When requesting the IDPF, be sure to cite the Freedom of Information Act.
As for the second question, though I have not verified it, I have found the following listed online:
Information on sailors who may have died while in the U.S. Navy is recorded on index cards. A description of how the individual was killed is usually included. These may be requested from: Officer in Charge Naval Medical and Dental Affairs Mortuary Affairs Branch PO Box 886999 Great Lakes, IL 60088-6999 Phone 800-876-1131 Ext. 621, 627, or 628 Fax 847-688-3964