My observation is most rookie cyclists take too long of a pull when on the front. I suppose they are trying to show how strong they are. Ideally, the pull should be 15 to 30 seconds unless there is a big disparity between riders. Of course, road conditions, traffic and safety trump timing and riders should only exchange when it is safe. An elbow flick depending on the direction of the wind works well. In team time trial on the aerobars, elbow flicks are not required and racers know the timing and drift into the direction of the wind.
Wind. There is nothing better for managing wind than a pace line of riders. However, the rotation should be into the wind so that the riders going to the back shield the advancing riders. On the exchange, the front rider signals or moves slightly giving the next rider room to take over. For a couple of seconds, the front rider shields the next rider from the wind as he takes over. If the exchange is made in the wrong direction, the advancing rider feels the wind and increase in power sooner. Now road conditions and safety trump this and riders should always exchange in the safest way possible. But if there are wide bike lanes, it is easy to rotate in either direction.
Constantly rotating pace lines work really well and rotate into the wind as I described above. I have found very few groups who can actually do this other than racing teams of racers who train and race together. One has to be very smooth and comfortable with a lot of skill.
Stronger riders... If you are much stronger than the other rider, double or triple the time at the front but do not increase pace. If you are bored and it is too easy increase the cadence and spin at 110 to 115 rpm. That will give you something to do marking time in the line.
Weaker riders... Do not overstay your welcome at the front. I cannot tell you how many times weaker riders get on the front and want to show the strongmen that they can "do their fair share" or that they are not weak. You are weak and everyone knows that and accepts it. What is not wanted in a weaker rider to pick up the pace, hog the front and fatigue early so that he is of no value later in the ride. Plus there are stronger riders who are bored with the pace and want the front so that it is harder. Remember, it is always going to get harder not easier as the day progresses. The best riders know their limitations and manage their energy so let the strong men do the work. That is really appreciated by everyone. If the pace is hard in the line, when you get to the front take a couple of pedal strokes and pull off. There is no shame in that.
Reading the pace line... Look ahead and not at the wheel in front. Do not overlap wheels. Use your peripheral vision to gage the distance of the rider in front and glance occasionally at the wheel to check your distance. In time this skill is easily learned and looking at the wheel is not required. Always have a plan in the pace line. What would you do if the guy in front slams on the brakes? What if he crashes? Do you have an escape route? Do you know all the people really well in front of you and their ability and habits? If all the options are bad, then increase the distance of the bike in front or get out of the line. Fast technical descents require separation of riders. Clear open good roads with wide bike lanes and light or no traffic offer good opportunities for group / pace line work with options if something goes wrong. And it will go wrong. Count on it and plan on it. If you have a plan, you dramatically increase your survival and keeping the rubber side down.
Pedal / coast riders... Do not pedal coast pedal coast pedal coast. First it is annoying to the person behind and the goal of everyone in the pace line is to be a good wheel to follow. A much better way to manage power is to keep the legs spinning and touch the brake slightly to kill a little speed if required. Of course if there is a downhill section then coasting is fine. What I am talking about is on flat ground. The goal is to be a smooth and predictable as possible.