I don't know of any recent studies, haven't really looked, but I've been typing in Dvorak for about two years and this is my take on it.
1. I don't think the superiority of one or the other is really the issue here. The issue is making the switch. Those studies are addressing whether it's worth it to switch.
The bottom line is that Dvorak is more efficient in terms of movement. It's optimized for typing in English (other romance languages are quite similar) and QWERTY just isn't.
2. From personal experience, I think that the mappings of punctuation are superior in Dvorak. I especially like having the dash and underscore easily accessible (next to Return) for programming. I also find punctuation more natural overall in Dvorak.
I've been typing Dvorak over 10 years now and more than anything I appreciate the comfort. Even though I type all day long I've never had a typing-related hand problem.
1. I don't think the superiority of one or the other is really the issue here. The issue is making the switch. Those studies are addressing whether it's worth it to switch.
The bottom line is that Dvorak is more efficient in terms of movement. It's optimized for typing in English (other romance languages are quite similar) and QWERTY just isn't.
2. From personal experience, I think that the mappings of punctuation are superior in Dvorak. I especially like having the dash and underscore easily accessible (next to Return) for programming. I also find punctuation more natural overall in Dvorak.