Is it possible to setup a special needs trust where assets are placed in a trust possibly managed by you that can be used for specific medical reasons but won't be considered for Medicaid.
http://en.wikipedia.org/wiki/Supplemental_needs_trustA printed wallet can work. I personally wouldn't find it to be significantly more secure or reliable than a flash drive. Personally if I was paranoid I would use both.
Bitcoins at this point is a risky investment and I wouldn't suggest buying more bitcoins than you can afford to loose. I expect it will either be a very good savings method or go to zero with little in between.