But in the application form they say "please d not apply directly to CBSA", so I left this bit for CIC. In my situation is it better that I get my own CBSA or leave it for CIC.
Get your own records from CBSA. Don't you want to know what CIC is looking at? What if there is a mistake? I'd want to know if what they are looking at matches up with my declarations.
Yes, I agree and there is no harm obtaining it for records. Would travel itinerary count as reliable evidence to confirm dates left Canada? Do travel itinerary and tickets carry any weight in the CIC assessment?