Can anyone tell me during background check of spousal sponsorship, do they contact all the employers listed in IMM 5669. DO THEY ALSO VERIFY EDUCATIONAL CREDENTIALS
Do you mean of the sponsor or the applicant? Why are you asking?
Assuming you're talking about the applicant -
Let's be clear: since both employment and education are not criteria they use to 'decide' spousal sponsorship, it's safe to say that they're not generally checking eg to make sure responsibilities at work or education degree corresponds with title or degree is 'valid.'
But putting untruthful things in there CAN cause problems - it's misrepresentation and can result in a ban.
And they may check some things if they don't seem to make sense or for security reasons, etc. To my knowledge this rarely means calling employers (but suppose they could if they wish). If they find things that don't look or seem right, they'll likely dig more (repeat as necessary).
So simple answer: tell the truth.