: Your social security #
Part 3: Date of arrival US: Should it be the first time I came to US as a F-1 or the most recent one I came back?
: I don't know exactly. Normally if you did not break the continuity (more than 180 days ) living out of US, you should use your first arrival date.
Part 3: I-94 #: Should it be the I-94 # I got from H-1b?
: This # is the same as your I94 # of last enry.
Part 3: A#: Be N/A for my case?
: You can use your OPT EAD A# (started with A, with 9 digits). This will also be your future green card #.
Part 4.3: native alphabet: should be N/A for us Chinese?
: You should write your name and foreign addess in Chinese.
Part 6: Do I need to fill the SOC code as a self-petitioner?
: Not very important. I did. No problem.