How are transport emissions not part of the EUs emissions trading scheme? ETS2 covers road transport, buildings and many small industry emitters, not covered by ETS already. The original ETS already includes air travel.
However going for 65% emissions reduction would certainly be a good move.
A few things. First of all the dolphins for the house boats need to be much taller. When you have flooding they have to be above the waterline to have the house boats not float about and so nobody rams them, which would be bad for the boat.
Amphibious public transport is not that great of a solution. Boats can be easily larger then a bus and with proper waterways, which a city would have. In terms of capacity a fairly small boat can easily carry as many passengers as a tram. They also are more efficent without wheels in water. Also you have a problem with doors and other parts which need to be opened often on a bus, since those nearly have to be under the waterline. That also is somewhat true for the ropeway. A ferry connection would be just as fast and can have the same capacity. So a ferry elevate rail interchange might be better.