Interesting video as usual. Awaiting part 3! Yes I think battery power works well on garden railways and I think in time it will be adopted by smaller scale indoor cousins! I have used Deltang equipment on my railway but found with points that occasionally interference caused unsolicited operation of points so went back to switches and servos although it is possible that water ingress caused my problems. I do like the complexity you have built in to your operation.
Briefly, yes. I do have one live steamer (a Regner Chaloner) but I've only ever run it twice. Because my main focus is operating train services as realistically as possible I find battery powered locos to be perfect - they are instant to fire up, I can run them at realistic speeds, they are ideal for shunting and will run all day without refuelling. I think, if I had live steam instead of battery, a full running session would take three or four days rather than one and a half.
They certainly seem to be similar. The Playmobil block I used for the Southwold Sharpie loco is quite different to the Otto ToyTrain style of motor block and doesn't perform quite as well. I think it might have a three pole motor rather than a 5 pole one.