For 1, you’d need to edit the scenarios.json file and add your profession to the ones listed as eligible for the lab challenge.
2 & 3 are why I punted this down to the Translations Team people. Hoping they can help you better than I can. (I’m vaguely familiar with the .mo being some sort of script-generated file from the .po files, which themselves are handled using specialized software that seems Linux-based, but I’m not at all familiar with the process in any useful detail.)
