it's too many questions at once.
So - Lulonga has a rudder (for me on channel 4) but it is placed under the inclined stern, and it has been tested that it works only with little efficiency, so I practically do not use it.
Location - I live in a small town Rožnov pod Radhoštěm, Czech Republic, Europe. The river Bečva flows through it. It is, as the experts say, a mountain-type river, for you it would be more like a stream.. We were here on the river with model Lulonga > 49.463001, 18.147153 The first photos - the lake in the park with my Capricorn model, the last photo - I think it's the place in Bečva where we were with model Lulonga.
I also run model boats on the small lake in the park, which is a little bit next to the footbridge. I have no other choice at present.
Angled Paddle Paddles - I covered this in detail on www.Paddleducks.co.uk which is mainly for paddle steamers. In the original, the inventors claim that wheels shaped in this way have better maneuverability.