Interesting topic.
All just my opinion:
Certainly casting order is very important and obvious if you watch everyone else.
But first off, people should watch the rhythm of the crowd first and how far out they are. If people next to the area you walk into are 3 feet out in 8 inches of water making casts that drift 10 feet in front of them when straight out, then try the same even if you want to be in 3 feet of water with your waders and casting 30 feet out. If you want to drift further out than their drifts or want to wade out much beyond where they are ask first or just stick with what they're doing. The further out you go, the more you likely are to scare fish AND upset other anglers IMO. Also watch the angle they take when casting AND reeling in from their drifts. Hopefully everyone is using about the same angles.
One thing I notice with combat fishing is how many times everyone seems to creep out a little further with time. I do understand covering water but a lot of times fish are pretty close to shore along seams with the main current. This is one prob I don't like w/combat fishing. I'll go to a drift I like and find people wading almost right where I want to DRIFT my rig LOL. And where I caught fish a day earlier! Of course this can work against me- if I want that drift where everyone is wading I can't- I have to adapt to what they're doing since they're there first. Now if I short drift and hook a fish 5 feet in front of them w/o crossing up other people in their drifts I might try to politely suggest the best drift might be close in and not along the far bank
It does make sense people want a 'good drift' and getting just a little further out than the next person sometimes frees up some drift space (esp if people aren't follwoing the ettiquette rules) but use good judgement about how far others are making their drifts and adapt to it. Hopefully more than two feet of good drift but who knows with combat fishing when it's thick...
One grandaddy rule is: first person there gets dibs within reason.
Try to be reasonable and courteous with anyone that was there before you. If you are courteous, many times they'll make a quick judgement of how well you follow the etiquette 'rules' (like casting order) in short order and let you in where you want. But be willing to accept their space unless it is obvious they are 'hogging' territory- if people are spaced 5 feet apart but then in one area one guy occupies 30 feet of space type thing.
And take your time walking in, don't run right out.
With sleds- they do have to get up and down river and being planed on top of water with speed is much less risky for them (and less disruptive to the water) to avoid bottoming out than slowing down and displaces less water so less disruptive to fish in some ways. HOWEVER, much like cars in the road boaters NEED to yield to anyone wading in the water. If the water is deep enough, be willing to lay off the throttle IMO and of course even if an idiot is wading neck deep in the middle of the channel you gotta avoid them (or maybe save them from drowning LOL). Many boaters know the river and channels well enough to know when they can and can't get away with slowing down. I don't own a boat/sled and haven't really actively and seriously fished rivers for almost 20 years, just sporadic trips when fish are thick enough to get allowed out:) . So if you think what I say is all one man's poo, you'd be right. Just my opinion though
Oh ya, one other Grandaddy rule is- it aint worth it... i.e. if you are getting upset enough to start cussing at someone, it aint worth doing it. Take a break or maybe even pack up and move on. Repeating a lot of what others said but thought I'd put in a penny's worth.
Of course the other IMPORTANT rules like take a kid fishing, be patient with them, share the wealth especially to newbies and people politely following 'the rules', make fishing enjoyable and not stressful, etc etc apply! Good luck everyone!!!
"Its the coming back, the return which gives meaning to the going forth. We really don't know where we've been until we've come back to where we were. Only, where we were may not be as it was, because of whom we've become. Which, after all, is why we left." -Bernard Stevens Northern Exposure