@Shinvergil

They're essentially canon, yes. If you want to get technical, since it's not directly first party, if anything happens in the show that causes a contradiction with the comics, the show will take precedence. Same as the info from the trading cards or toys, canon from the show will override second and 3rd party canon, but until a time that it does, you can more or less take the comics and toy information as canon.

The plot-lines of these comics are apparently ok'd by Hasbro before they go into production, and the first scenario for the Rarity micro-series was rejected because it was actually identical to an upcoming Season 4 Rarity episode, so there is an effort to make sure the show and the comics don't mess each other up. Still, I wouldn't expect anything that happens in the comics to be directly referenced by the show, at least not right away.