TAZ, to answer your last question: you don't need to ask for a delivery signature. I've sent to that address with Fedex. I didn't know if they are in the habit of signing parcels so I didn't risk it. You can track with the tracking number. About the other stuff, are you H1B now? I didn't fill a I-765 but you need to understand that it is to your advantage to maintain your current status until the day of the interview, so if you are on F/J/OPT you should understand that submitting I-765 will end that status. If you are H1B and it is not expiring any time soon, you don't really need I-765 unless you want to change your employer etc. Just my 2 cents.
Thanks aos13 for your response.......I am on H1B, expiring Nov 2014, however, I may have to change jobs before the interview because of the sequester....It is quite uncertain, therefore I would like to file for 765, too. I really appreciate if someone with 765 experience could help me with my questions regarding to file the 765. Thank you all