There is much to be said for our Continental neighbours attitudes where one is expected to raft alongside. However there is a tendency for boats to raft alongside another boat when they would be quite capable of going alongside either a wall or pontoon. This has the effect of restricting mooring places for larger boats and I for one am happy to put my boat alongside a smaller boat. Boats sit in water and their weight is carried by this wonderful substance, not by the boat inside them unless its blowing a hefty beam-on wind.
As for children, they are wonderful and ALL of us should encourage them and be encouraged by their presence on/in boats and on the water. This is where they learn and if you feel that your standards are not being adhered to, then a gentle word as they cross your deck will be effective. However I have NEVER kicked a kid out of my cockpit as they cross my deck but have many times stopped adults and redirected them forward. Perhaps they should have started sailing earlier with their parents and learned some basics.