What an awesome harbour set up, congratulations Arizzo and Sascha! Absolutely breathtaking, I'll be looking at the pictures for hours noticing new details.
Does this event get any support or recognition from Geobra? This is the sort of thing they really need to show interest in, even just one juliro sales executive turning up for a couple of hours to chat with the contributors and the public, to see what adult collectors are doing with their company's product, and to find out what they can do to encourage more sales. The single biggest set I know of using this colour of wall is the 5727 Pirate Dungeon, and there are a lot of parts in your layout that I didn't know even existed.
I can only imagine the hours and the energy required for planning, ordering parts, designing the layout and each of the buildings, practise set-up, packing and transporting, re-setting up and then the breakdown afterwards. Most of us have done some small scale layouts, but rarely anything on 1/10th the scale of this colossus.
It's a great shame that the 4294 Lighthouse was designed with the apparent intention of preventing it from being used in such a set up. At the time of release I was in the camp arguing that it didn't need to be modular, but now, if I haven't before, I'm eating a large wedge of humble pie and admitting it should have been made with System X.
The recent trend of for Playmobil buildings that stand alone, and CANNOT be connected to anything else, may not stop avid collectors from creating such massive dioramas, but if they have to use the modern sets (e.g. Egyptian buildings, the lighthouse or the Dragonworld towers) they'll become displays of collections of small sets, and not a massive, integrated whole.