My personal list of the OSM projects for Slovakia (assorted by importance):

• house numbers adding
• cyclo routes adding
• tracks adding (based on strava heatmap)
• new bildings adding based on ortophoto
• wikidata and wikipedia tags adding
• waterways adding
• railways tracks (re-)numbering
• cry me a river - river precising
• run forest run - forests’ precising
• changes sets` review requests from new users
• railway lines (long distance, commuters) - https://loom.cs.uni-freiburg.de/global
• school/ agricultular (ex. JRD) areals
• 3D buildings (churches, POI buildings…)
• roundabouts precising
• rail and informal path crossings’ access (type: node child railway child (highway=path -access=no)) -maxspeed -missing power lines

ToDos:

Welcome tool - https://welcome.osm.be/europe

Surfaces - https://data.humdata.org/m/dataset/slovakia-road-surface-data

JuRaVa cycloroute - to map by armchair mapping

Oprava názvov ulíc| Wikidata