I need to visualize different types of data points and routes on the same OSM map.
As far as I know, you can only plot one visualization using the OSM nodes.
Is this possible? Is there any means of merging different visualizations into the same map?
This is not supported by the OSM nodes. To work around this, you could try to implement it using a Generic Java Script View node together with Google Maps, this should give you a bit more flexibility.
See here for an example: https://www.knime.com/nodeguide/visualization/geolocation/choropleth-world-map