As for surfaces, I think one can adapt to just about any surface, it's just a matter of whether it's worth it or not. If you (Laura) are training for triathlons, you need to worry about speed, right? For me, barefooting is key, so if I had nothing but gravel, I would try to make a go of it and see if I could hack it at decent paces. BTW, what do you mean by "tar-covered-chip-seal-that-never-dies"?
As for the Moc3s, I never wear socks when I use them as back-up, but if I head out with them on, that means it's pretty cold already, so I will start with socks on too if the temps warrant it.
The chip sealing used to be just part of the process and after a while the road would be made smoother; or, they wouldn't do it SO often and it would have time to wear down during the year. It seems like they are doing it more often AND using something that just stays pointy! hmph!
As for speed, I realize I'm not preparing for the Olympics or anything of that sort, but I would just as soon run according to my capabilities and work on improving those. It makes it more fun.