you like to play easy and respect it, but this discussion is for competitive players who would like to change things
Sorry dude, but this makes you sound slightly arrogant. I don't think lua is an inexperienced guy that does not want competition! But you are missing, or confusing, something here.
Your statement is that people who sit back, build a massive hammer (maybe for endgame WW rush?) get lots of off points for their big hammer from killing robbers, while people who use their hamemrs in game and lose it once or twice will have less robbers and thus less off points. Well, if they lost their hammers AND have skill, they will have killed quite a few real deff troops doing so. These are twice as effective as robbers, so they are easily on top of the laidback hammer builders. If they are really good, they lose only a fraction of their hammer and still kill a decent amount of deff, thus enabling them to get big robbers AND "real" deff points. So I do not see the problem in the system as it is, regarding your criticism.
However, I do see a problem in the robber system: Nowadays, it is a much "better" strategy to focus on deff building, accumulate a huge number of players and use auto-generation of treasures from robbers to achieve big numbers of VP. At the same time, stealing treasures from other kingdoms has become increasingly difficult (ditch, push-notofocations and such).