"Air Force" MPs have been around since the RCAF where the vast majority of the Air Force Policemen were employed as site security for those items that Canada never had. If there is an "invented" MP uniform it would be the navy one as most MP functions, particularly that of disciplinarian, were filled by the shore patrol, usually specially trained pers of hard sea trades. SP was not their primary duty and they would only fill those functions when required, once their ship went to sea they were back to scrapping rust etc. Once the glad bags came out MPs were eventually posted to every CFB and the duties and responsibilities were made pretty much the same at each base, aside from places like the MP Pls and Bn MPs.
SOF: No we don‘t beat suspects, we are held to the same laws and standards (in some cases even higher standards) as civilian police. As for Borden, it isn‘t an Air Force base, it‘s a CFRETS base, it doesn‘t belong to any element. There is a strong Air Force presence there with 400(?) Wing and the Alphabet school but the primary purpose of the base is to host the various trade schools. As for which bases MPs serve at, they serve at them all. Air Force can serve at Navy bases, Navy MPs can serve at Army bases and Army MPs etc. As has been stated, "purple" trades are not colour coded when it comes to postings, although I do know of a MP field Platoon that only has 4 "Army" MPs in it so perhaps that poetic justice on those that chose Air Force blue and Navy...