Mother sponsorship, timelines, osap and ei question

Hello,

I had applied to sponsor my mother last year. i havent heard anything from the cpc mississauga except a letter 6 months after the initial filing (and making numerous phone calls) stating that they have received the application. they didnt give me a file number yet. i was wondering if that is normal.

also regarding the lico, which is 33,197 for me (as me and my wife live together and are sponsoring my mother). i was on ei this year for a few months while working part time. would the money i received from ei be added to me and my wifes income while calculating LICO?

also i am planning to go back to school next year and going to get osap, would that affect my application in any way as long me and my wife maintain our LICO?

Also on one of the threads in this forum i read that sponsored parent, while in the immigration process, is now allowed to visit their sponsors in Canada and stay here as temporary residents. Would someone be kind enough to shed more light on this process as my mother is alone back home and is completely dependent on me and as the pr process is around 4 years, it would help a great deal is she can temporarily visit me.

Thank you for your help.