good drill for crosshair placement is going into a game and trying to keep it at head level the entire game including pre round and while your buying, hooj uploaded a video like that recently and has others on movement/peeking; running dm's to get it more consistent helps a lot too
i'd also recommend watching how a pro plays brim on haven/other maps, if you do !pwea in chat it'll show you people you can watch. your smokes are a bit of a problem since normally you want to smoke the direct entrances to site but yours at least in the first 2 rounds are kind of all over the place; like smoking the entrance to garden on A that would work if your team was pushing up but your reyna got one and dipped, so you would have been better off saving it and double smoking a (even with the wall since it hadn't come up yet i'd just auto double smoke it but I could be wrong). Then for smokes on round 2 you smoke window which is good if people are peeking and you want to fight, but thats after swinging the jett when you saw them pushing up B, I'd have smoked B main then peeked. The second smoke also can't be capitalised off of even if you pushed down it would be limiting space for you guys