some questions regarding background declaration item 10 Education

Hello friends,

I am preparing my application forms and materials for application to CIC buffalo and getting confused about some questions.

1. I am nominated under the "pilot international graduate student stream" in Ontario so I have a two years master's degree. In the background declaration form item 10 Education, there is no item mentioned as graduate school. Should I put 2 years in the "Trade school or other post secondary school" box?

2. I am right now living in a bedroom in a house and I don't have my own home number. However, I do have cellphone for daily use. For form "Application for permanent residence in Canada" item 16 "your telephone numbers", should I put N/A for the "at home" while put my cellphone number under "alternative" or should I put my cellphone number under "at home" directly?

PS. Can any friend tell me if CIC officer may contact me by phone? How do they usually contact the application if they need further info?

Please help me and Thank you very much!