Hi,

Your one word "fix" (what? (Visit the good comments wiki!), shows a lot of broken area outlines. See OSMI https://tools.geofabrik.de/osmi/?view=areas&lon=14.24910&lat=45.41686&zoom=12&baselayer=Geofabrik%20Standard&opacity=0.50&overlays=duplicate_node%2Csingle_node_in_way%2Cduplicate_segment%2Cway_in_multiple_rings%2Cintersection%2Cintersecting_segments%2Cring_not_closed%2Ctouching_rings%2Crole_should_be_inner%2Crole_should_be_outer%2Cinner_with_same_tags%2Cways%2Cduplicate_node%2Csingle_node_in_way%2Cduplicate_segment%2Cway_in_multiple_rings%2Cintersection%2Cintersecting_segments%2Cring_not_closed%2Ctouching_rings%2Crole_should_be_inner%2Crole_should_be_outer%2Cinner_with_same_tags%2Cways

As for breaks in forest that pass pipelines, powerlines, fire breaks etc there's the man_made=cutline tag (571,000x used) https://taginfo.openstreetmap.org/tags/man_made=cutline#overview with a dozen types which will render a nice grass like line through forests and scrub. Makes mapping those quite a bit simpler... just draw a line parallel to the powerline, pipeline, ski piste and done you are.

ciao

Sample cutlines https://www.openstreetmap.org/changeset/154376601#map=18/41.84357/14.07367