Now that's neat Joe!
My other passion, apart from paddlers, is historic water speed record boats - I've often fancied trying a really high powered paddlewheel driven boat, and YES I'm being serious!
I think the pitman arms and the steam plant would have to be ditched in favour of a geared drive and a high power electric (maybe brushless) motor - I'm sure it would work, but how fast it would be compared to a more normal surface drive setup is anyone's guess!
The other major problem is making a paddlewheel light enough and strong enough to cope with 25-30,000 RPM