Hi Paul,
Some valid questions you have there - I'm sure there'll be some different answers from different people.
1. My Taipan is trailered using the AHPC 'no-tie' system which is essentially a frame with a set of cups that hold underneath the front beam. This takes most of the weight of the boat and the sterns are supported by a cup on each side. Works really well and don't have any problems as long as the cups are free from grit and stones etc before going long distances.
2. This is a tricky one and I'm sure there isn't a difinitive answer - especially given that the F16 class is still reasonably small. People have different ideas, platforms, weights, mast materials, mast setups, sailing techniques and experience. If all these were standard across all of the fleets then a difinitive answer 'might' be possible - but only after extensive independent testing in controlled environments. See what I'm getting at? Whilst there are faster sails than others in some circumstances, generally the nut on the tiller has more to do with speed around the course. The only thing you can infer is that (in general) newer sails are more closer to their designed shape than older ones and therefore should be more efficient and faster - though this isn't always the case either!

3. Not concerned about putting foot in foot loop. The trick is to make them small enough so that you can jam your foot in there and tighten your ankle to keep you in when you have a small nosedive. You also need to make them large enough to release your ankle easily when you have a really big stack over the front and go flying. Also, don't put your feet too far into them - its the same problem that horseriders have when they fall off. If your foot is too far into the foot strap thingy, then you can get one jamed in there and then get trampled and dragged by the horse. The thing I'm most worried about is having my foot in the strap and then falling off around the back as the boat accelerates twisting your ankle the wrong way. Doesn't worry me too much though.
Don't sail offshore all that often so don't carry a mobile phone but its not a bad idea.