You fish a lot like I do, and you're 2nd paragraph sums up the my views on comps quite well. I took pages to try to explain that!!
I'm not opposed to comps. I have a slight interest in them. If they were set up to test skills I have more interest in, I'd be much more interested. Where I disagree with you is that, I do think it's possible to set up a comp that way. Why not? They don't rope off sections of streams or anything.
Just set the anglers loose, to go wherever they want, with a controller in tow. I'd say set loose at 7:00 a.m. in the morning. Anglers have 8 hours of streamtime, which can be done anywhere, anytime that day, the controller keeps track. Meet back Sunday morning....
If you want to encourage a variety of tactics, then weight the results for the stream. i.e. 30 brookies from stream X equals 10 browns from stream Y. Could discuss the weighting, but I see it as feasible. May take some trial and error, but when you notice everyone using the same tactic repeatedly, you know it's overweighted. Adjust until you zone in on a good scoring method.
I'd love to see what the "pro's" do, given the opportunity to maximize their results, like the rest of us can. Bass tournaments already do this to some extent. They're limited to a large lake or river system, but they can go wherever they want within those confines, and the controller comes along. Likewise, you could put, say, a 30 mile radius on it or something, to keep people in the general area.