And hows going? Any playable map?

About Template editing: That's actually only needed if
1) You want to add components to entities for this map. You cannot do this in object editing alone, so you have to subclass your template.
2) You want to create entities dynamically from LUA and don't want to write all the changes from there, but nicely setting them in some editor.

If you just want to manipulate some properties, you can also use the Object Editing tab.