Hello,
As far as I know, an applicant is suppose to provide all their respective details till the date of their application submission. I have seen few applicants who after submitting their applications, travelled to different countries without informing CIC n they got their application approved n got the PR aswell. I dont think there is any such rule/condition of CIC about informing the travels u make post submission of ur application. If I m not wrong then the requirement to submit a PCC is only if u stayed in a particular country for more than 6 months in a row (not in discontinuation). So in ur case as u r on a tourist visa which I guess is valid for 3 months only, u wont be staying in UAE for more than 6 months in a row. (Still confirm this on CIC website for latest update related to PCC requirement).
Coming to your second question, YES, UAE will NOT issue a PCC to people who visited UAE on a tourist Visa. If u r applying for a UAE PCC, they will ask for Emirates ID or Resident ID, both of which are not issued to people on tourist visa.
Hope this helps.
Regards.