Need help with TN visa. Canada/US tax filing

[Canada06]

Hi, I am a Canadian citizen who is in US working on TN and living with my son from August 2015. My job is a contract job which will end in Dec 2016. My husband is working in Canada. I worked n Canada for 12 days in Jan and had gone for vacation until June 2015. Then at the end of July 2015, I came to US. I still have my Canadian DL , Canadian leased car, Canadian checkin RRSP & TFSA mutual funds and RESP accounts.? Now my questions are

1. What should I file in US? Do I need to get SSN for my son in order to get dependent tax benefit?
2. What should I file in Canada? How to claim daycare expenses of my son paid here in US in Canadian tax filing?
3. When I file Canadian taxes, is there anyway to file separately as I don't want my husband to know my US earnings because of some complications.
4. At this point I am not sure whether I will go back to Canada or continue to stay here after dec 2016. What to do with RRSP & TFSA mutual funds and RESP accounts.?
5. Also, I am thinking of buying a house here. Will it be a wise decision in terms of money savings.


Thank u.