Need help pleased,Reference employment letter and form

[mawin]

Dear seniors
I am new on this forum and writing to ask for assist some information from seniors.
My situation there are;
1.I worked as cook on 9th August 2011 - 12 February 2012 (6 months) in Alberta and I got reference employment letter on 13th February 2012.
2.I work as Thai chef since 1st August 2012 till present in Ontario
My questions are
1. Is it possible if I submit reference employment letter from cook and chef together but reference employment letter as cook I got it since 13th February 2012.
2. I am single. Do I have to submit•Separation Declaration for Minors Travelling to Canada (IMM 5604) form?
3. Regarding to NOC they had changed from 2006 to 2011, which NOC I choose to get it to fill out the form?
NOC 2006 Cook= 6242 but NOC 2011 Cook=6322
NOC 2006 Chef= 6241 but NOC 2011 Chef=6321

Please,seniors kindly give me the information. Thank you in advance.

Regards,
Mawin