If you have all the required components you should be able to use MapSetToolKit to INSTALL the mapset. Click the INSTALL button on the bottom right of the opening screen. Then add the TDB, overview map, mapset directory, and registry name in the popup and click INSTALL on the popup.
Re. osm2mp. It gives a direct translation of OSM data into MP. With a large map maintaining routablility is difficult with osm2mp because it converts routing errors, like self connecting loops, into MP format. These then have to be removed manually in an MP editor. mkgmap automatically fixes these errors during compilation, so none of the manual error correction is needed.
