We've done many trips with many different people. I think what worked for us was knowing the people we went with would be good on a boat. We also didn't ever charter with anyone that was rigid - being flexible is key and going with the flow. In all our trips we only had 1 person that didn't contribute much to helping cook, sail..etc. There were 9 of us so we had plenty to pick up the slack (and with 9 there really wasn't any slack to begin with). So we just let it go and it didn't bother anyone. A few of the trips we had friends bringing someone with them and while we didn't know them, we trusted our friends to make a good judgement on whether or not their friends/family would be good on a boat.

As far as your examples -

Eat at restaurants or cook on the boat?
Sail or sit on the beach?
Neat or not?
Breakfast Beer yay or Breakfast Beer nay

I'm not sure any of that matters. We've done all the above. The neat or not might be the only thing that could be an issue, but if someone isn't neat, as long as they keep that to their cabin it shouldn't be an issue. No matter how big a boat is, it is still small.. so it does help to set a guideline on where stuff should be stored so as to not have stuff all over the place.

I'm not sure if the above helps or not, but it is whats worked for us.