Chassidish means the full garb, shtreimel and bekeshe included and is a devoted follower of one specific Rebbe.
Heimish is more like jacket and gartel (double breasted suit preferred)or with one or more of the following options: Bekeshe with down hat; jacket with up hat; beard; trimmed beard; no beard; usually with chassidishe havarah; is a follower of one or more Rebbes but more passively than a full fledged chossid…….That’s a start
Fellas- am I on the mark?