Really good points though, it didn't occur to me that someone would be willing to go "on the record" but not be actually recorded.
There are some other solutions that use keyboards that wouldn't be as intrusive as a keyboard or tablet (and may be something to consider for you personally if you have a disability in only one side); things like portable one-handed chorded keyboards: http://www.handykey.com/ and http://chordite.com/