Since our main purpose of migrating is for our daughter's university education and her future, I was wondering happens if we return to Kuwait after completing all the landing formalities (PR card, SIN, Bank account etc.) and our daughter is enrolled in an university in Canada and she continues her studies there.

If suppose we do not return back to Canada within the three year gap in order to retain our PR status, what happens to my daughter's PR status. Will she be eligible to continue staying permanently in Canada and get a citizenship. Or as a main applicant, since I am not retaining my PR status, will my dependants who are in Canada will be affected.

Since the job opportunities for 45+ looks very bleak, we are just wondering about the above option.

I think you will have a problem, as you are the principle applicant.
Its through you that your children will be granted citizenship.

You must maintain PR status for you daughter to be legally here,
just what i think...
but wait for an expert advise