3) Unlike many other alpinists, I do not use trekking shoes for approaches. I use light trail running shoes (La Sportiva Slingshot and Crosslite), combined with your brilliant Tarsal Loks. It gives more stability than a trekking shoe. I also use this combination for long runs (40km+) in harsh mountain environments back home in the Austrian Alps. I am currently working here in Canada on a landslide side, where I use the Tarsal Lok whenever carrying heavy loads.
The hardest test I put the Tarsal Loks through was the approach to remote Pik Leningrad University (6222m) in SW Tajikistan near Afghan border. I used the Tarsal Lok over many days of strenuous hiking, and my trail runners and Tarsal Loks carried me and my 30-40kg backpacks without problem through moraines and over boulders.
This year (August) two friends and climbing partners will try to ski Pik Soviet Alpinists (6366m) and Pik Revolution (6974m) in a remote corner of the Tajik Pamir. I will use the Tarsal Loks again for the approach. I also convinced one of my partners (former marathon runner) to get a pair of Tarsal Loks.