Igor, I can only address #8 with my experiences, but I have only
found two things in life that "carried over" into other sports: high school
wrestling and the O lifts. Wrestling in high school is one of the rare times in life that it is just you and one other person. If your team gets pinned and pinned, but you win...well, you won.
O lifting is an amazing sport for carryover. I once, on a stupid bet for a twelve pack of beer, raced a ten kilometer run without ANY (zip, zero, nada, nothing, any) running in the past year or two or three (or maybe five years), but I was getting ready for an O meet.
Lots of people...lots...finished well behind me. In fact, this Nazi psycho running chick at the job I had at the time finished behind me, too. O lifting gives your VO2 intake a ride every workout and it carries over into other sports. Moreover, it is much easier to go from a 300 pound snatch for one to 50 one hand kettlebells with a heavish kettlebell, than it is to do 50 one hand snatches with 72 pounds to a single with 300. When I was at Skyline College, one of the geek runners said that "we work harder than you guys (throwers)." First, I challenged him to fight (actually I told him to attempt a bizarre act by himself), then, I thought about it. At the time, I was snatching in the 240's and Clean and Jerking in the low 300's, plus tossing the discus over 170 and the shot over the low 40's. He would do repeats of the 400 in the mid-60's as much of his training. My question: if you switched us for, say, $1,000,000 to the first to repeat the others workout... who do you bet on?
I feel that a power athlete can always build the endurance end up quicker than an endurance athlete can build up the power end. As a personal challenge to yourself, simply get your snatch up to 300 and your clean and jerk up to 385 at your current bodyweight. This should not take long. Then, test your kettlebell endurance and see if you have lost or maintained anything.