Sounds like a great endorsement of cats
Instincts only work when your body knows what is happening anyway. In each of my crashes, had I been aware I was about to crash, I wouldn't have
You're on a topic I know something about. Reaching with hands in a fall is influenced by the circumstances, it's not automatic. I did a trip and fall a few days ago, dragging a toe on a top step. I pulled my hands and knees towards my chest and rolled, 'instinctively' (that cost me a half dozen micro bruises, but probably avoided a broken wrist). If your face is protected, and depending on how much time you have, and how familiar you are with what's happening, you'll try to prioritize to minimize the damages. May be you'll pull your hands in. I seem to leave my hands on the grips in falls, which might be influenced by the brush guards (why don't they have those on all bikes?).
No. Any decent motorcycle gloves serve both purposes quite well. That's what they're designed for.
A common home bench grinder turning at 3250 rpm with a 6" wheel has a surface speed of 60 mph. Put any kind of motorcycle glove fabric on that you like and watch what happens. A paved road is pretty much a gigantic bench grinder.
Yet plenty of people-- racers for instance-- have crashed without suffering a single square inch of road rash to their hands or elsewhere, because their gear works. Often leather takes so little damage it's still usable after multiple hits.
I'm fond of my brush guards because they saved some fingers in an initial impact with raised concrete. Nothing else could have done that. Your reference to long fast slides sound like track experiences. I'm certain a lot of thought goes into the choice of aggregate and how the surface is finished for motorcycle tracks, to minimize the consequences of crashes but keep traction in wet weather. If you were to ask the track manager what grade of aggregate was used in the paving I bet he could tell you.
I've heard amazing stories of long long slides with no harm to anything and other stories of those fancy leather suits being turned in to cheese casserole. There are a lot of things that decide how things turn out.
Take a look at dirt riding gloves sometime, they are a joke. My gloves aren't deer hide, that would be expensive, it's split cowhide and not the good stuff either. I use work gloves partly because I'm often riding to a work site to do some actual work. For my speeds and terrain that type of glove is more than adequate, and certainly no worse than dirt bike gloves.
I have never heard of such things myself. I've seen mentions of shoddily made leathers busting seams, but never the leather itself actually shredding through entirely due to abrasion.
And asphalt is a different surface than the ones designed for a grinder.
And race track surfaces may be a lot different from road paving, and tracks have big clear grassy areas to slide on to and may be no lamp posts or curbs or soccor moms in SUVs. I'm imaging that race suits have hard plastic parts in the most likely wear areas and those are going to be effective against pavement. How long leather lasts against pavement is going to have a lot to with the microtexture of the surface. With asphalt that's determined by the type of aggregate and how the surface is finished. Race tracks may be much friendier to leather than a lot of public roads.
Being able to use both hands makes a world of difference, even when you're just buying a bag of chips. My head is by far the most comfortable, handy place to carry my helmet. I'm not comfortable leaving it in the helmet lock most of the time, since I'm usually in the middle of the city with tons of people around. Also, if I'm carrying my helmet by the strap, I need to avoid carrying it on the side where my keys hang on my belt so it doesn't get scratched. Having a flip-face has really made my day to day life significantly more convenient. I mean, that's just me of course.
