I've never heard of flying models in one pattern only, don't think theres a club in the UK that does that, I would definatly never join one. There is a general pattern based on wind direction but that makes sence. The only difference is if you are doing something unusual you call it, "landing", "taking off", "Low pass left to right", "Low pass right to left", "Dead stick" "loop up the middle" and my usual favourite "I'm messing about low level call if you want me out of the way" .

I've always used the rule that mid-airs are always bad luck, don't fly what you can't afford to crash. I'm sure there are occasions when people are in the wrong but they are usually incidents where some arrangment should be made (help repairing etc..) like a mid-air on takeoff or on a landing where some respect should have been paid to the "called manouver".

As people have said, don't fly with the wrong people or the wrong models. If a large or a fast model takes off just give them that slot and wait till after, the same for heli's and aero's. Its supprising how little curtesy some modellers have, at the end of the day we're all in it for the fun.