My comment regarding trolling motors was my "opinion" based on comments from my friends and my experience "poling" on the flats. But I have never used a trolling motor on my boat because I don't want to add another piece of machinery and lose storage to a couple of more batteries.
I think trolling motors are great when you are in more than 3' of water. In fact my experience has been that my outboard does not spook fish in 4' of water. The fish move away from the boat but once you turn the engine off the fish will move back and start hitting a fly. How ever when I get in very shallow water the fish get much more skitterish. It can be very hard to get near them even when poling and I just think the noise of a trolling motor will cause problems. Personally I love to stalk the shallows and some how poling makes it seem more exciting because you are moving the boat yourself.
However in your case because of the weight of your boat I would recommend a trolling motor because I think it would give you the mobility you need in shallow water. Even if you scare some fish in shallow water it will still catch you more fish in the long run. One of the guides I know down in Chatham installed a trolling motor last year. Next time I see him I'll ask him how it's worked out on the flats.
When ever I give someone my opinion I'm always reminded of a day on a local pond when I told my younger brother to stop wasting his time casting into 10" of water. Two seconds after those words were out of my mouth he hooked and landed a 6 pound largemouth bass. Sometimes we think we know more then we actually do. Ive been fishing for over 60 years and still have a lot to learn.