Yes, we are using the wired Ring right now. As our tests have shown, it is a lot more convenient than it looks like at first glance.
We are also thinking about a wireless version. Although wireless ring is not impossible, it is quite complicated. You can find more info on Wireless Ring page.
Nothing serious, the ring will just unplug from the device. The micro USB type connector on ring wire provides protection in such situations. The wire simply gets detached instead of getting torn off, and can be easily reconnected later.
If you are building ProgArm yourself, make sure that you use such connector/port combination that fits loosely in each other. Sometimes it becomes better after a several hundreds of plug/unplug operations. If your connector fits too tight into the port, then you are not protected from the unlikely situation when your wire gets stuck somewhere.
You can also read a discussion on 2014-08-10 ProgArm 0.2 Is Here.
There are reasons why a display is not strictly necessary for ProgArm.
Currently we are using no display at all, but we are considering this possibility. You can read more on [[Display?]] page.