between the 3, the 10w60 is actually made from the thinnest oil, and propped up the most with viscosity improvers. Viscosity improvers could break down partially during use, so the oil likely gets thinner towards the end of the oil change interval
both the 10w60 and 10w40 are likely made from groupII base oils, 5w40 is a hydrocracked groupIII and has the best oxidative stability. the picture in the thread you linked to (post #35) shows the result of oxidative breakdown, the varnish like deposits in the timing case and possibly hastened the demise of the timing chains. The oil needed changing sooner in case of that engine.
If you go to 0w40 you might get PAO/ester based oils with much better stability yet. 0W30 is the same but (counter intuitive) heavier base oils and less viscosity improvers, provided you get A3/B4 rated oil.
As long as there's no thinning of the oil through viscosity improver breakdown or other cause, the higher HTHS oil will result in higher oil temperatures and in more fuel consumption. Kinematic viscosity has an impact aswell, but much less than HTHS viscosity.
Nano particles in oils have been the topic in many papers and studies in recent years. They seem to reduce both friction and wear, but the exact effects are dependant on the exact chemistry. I've not yet used such oils though.
Viscosity is the first line of defense against bearing wear, but is not effective to combat cam/ring/piston skirt and chain wear. You need anti-wear additives there. MoDTC or MoDTP are good, plenty of ZDDP aswell but also calciumsulfonate is both a detergent and anti-wear agent.
I would go for an oil with a narrower viscosity spread. What is the coldest temperatures you're likely going to see? All else being equal I prefer a 10w40 over a 10W50 over a 10W60... a 10W30 can be made without viscosity improvers so viscosity loss through permanent shear isn't an issue at all. Alas are not all things the same, the lower viscosities tend to get stronger add packs...
with the temperatures you're describing, I would go with RED LINE High Performance Synthetic Motor Oil 10w-30
Look for low Noack% and high flash points to find high quality base oils... and if you google for "VOA" or "UOA" of a certain oil you can find out how strong the add pack is. Bear in mind though that Ester oils are quite different from all others, in that they naturally have friction and wear reducing properties owing to their affinity to metals (which petroleum oils don't have). that's why some oils contain a few % esters just for friction reduction (magnatec's claim to faim aswell).