Hello Anshuman,
The duration of job may not hold as much weight in your application. They do try to see if you are employed or not.
From what I have read in other places, it does seem that with a spousal application the financial scrutiny is lighter and of a different kind. (That you are not entirely dependent on EI etc.)
Regarding the tax papers, CIC does need a copy of one of the tax forms, that you can get by calling CRA and requesting. If however, you have not filed ANY tax at all, it may be beneficial to talk to a tax agent and file for all the previous years, no matter what the income level is.
Hope this helps and others can add value to this as well.
Cheers and good luck.
