Called IRCC Agent and received this information. Might be useful for some of you guys as well
Signature
1. Sponsor can sign forms, scan it, and send back to Parents. Parents then can sign the forms where required and Mail to IRCC.
2. Parents can sign the forms, scan it, and send back to Sponsor. Sponsor then can sign the forms and Mail to IRCC.
I asked 4-5 times if signing the forms by hand and scanning to send back is okay? and all times she said yes. She just said, it has to be signed by HAND and not electronically.
IMM 5768 Gross Salary
The Agent said that it has to be for each year separately.
For Example, if you are working for employer 'X' since 2 June 2017 until now.
Then you put it like this
From: 1-Jan-2019 to Present, then include your earning to date when you sign the form.
From: 1-Jan-2018 to 31-Dec-2018, include your pay for that year.
From: 2 June 2017 To 31 Dec 2017. In Gross Income put whatever you earned.
Then From 1 Jan 2017 to 1 June 2017 if you were working with employer' Y' then put out that details.
Also, if you work for multiple employer at same time, then put that details even if it is overlapping.
Hope it is useful information!