real talk, does a wood bar reduce road buzz or is more comfy in any way? does OP or anyone here actually ride one?
anyway, a broom handle is gonna be cheap pine or something that will snap on you immediately. but if you used hickory or something, it should be safe. think about the handles on axes and sledgehammers. they undoubtedly withstand more stress than the occasional pothole.
but: is there any advantage, or is it just for personal flair or whatever?