In reply to humptydumpty:
Easy answer: It depends...
More involved answer (and my opinion only based on half a dozen El Cap routes):
1. If the faster party will obviously be out of the way pretty pronto - certainly if they're an IAD team, or if they're gaining at 2 pitches for every one that you climb. Otherwise, easier to agree an overtake at an overnight spot - fast team should plan to get up really early so as to create min disruption. Top tip: if you do let someone past worth agreeing that let you back through if you catch them up - I made this deal with an Italian pair pre hauled on The Nose (we'd fixed and were hauling). They got into a huge clusterf@c# and ended up bailing. They would have stuffed our trip if we hadn't passed them. In another passing manoeuvre on Salathe we did the six pitches off El Cap Tower in just a couple of hours then spent 6 hours waiting for a SLOOOOOW American team to do the pitch to Long Ledge. They took the hint of some slightly grumpy looks and waved us through in the morning.
2. I would say as soon as they've left the stance (as they will be faster jugging and hauling than you will be leading) however I'd say it would be your lookout if you get to the next stance before they've cleared it.
3. Squatters rights - if you aren't there then I think fair game. Safer to just fix one in which case the belayer can stay and baggsy
4. Can't see why you would want to, but it shouldn't be in the way if you really want to climb the pitch.
5. Yes, but why not just wait - unless you are overtaking you don't gain much.
Better than all the above advice is just to pick a route without anyone else on it and move fast enough to stay ahead of anyone who might start - we've only ever encountered slow traffic on the trade routes of The Nose and Salathe, otherwise we've always had a clear km of rock between us and the top, and I know which I prefer!
Enjoy!
Cheers, Dom