@Xekoslav Slovak. Further south you go “bre” is more common and frequently used, although in the deep south it becomes “be”. Stereotypical “bre” Croats use as joke is typical for Belgrade, but it can be heard everywhere, in Vojvodina it’s mostly used when you’re irritated, for example “Šta radite, bre?” can be equivalent to “What the fuck are you doing?”.
Some years back jokes about new Croatian words were popular here, like “zelenočohano četveronožno štapopikalo” for pool. I know that about kruh (it’s kru’ more often) and zrak, but I have to admit I like hleb (hljeb) and vazduh better, since it sounds the same or similar to words other Slavs use, same goes for tisuću, I prefer that to hiljadu,  which is of Greek origin. But trying to speak ekavica isn’t so common. I study with a lot of people from Bosnia (Serbs of course) and they despise people who switch to ekavica while here.