Yes for sure there are lots of problems! I don't remember the specific details of how they were getting around the issue of the correct differentiation state. One way of doing it (though incredibly work and cost intensive) would be to just filter out the types of cells you need but that would not be efficient.

The kill switch thing would definitely be a problem ethically. What if someone used it in a healthy person that wasn't having problems?

Yeah, I truly hope we get stem cell treatments going, all of the literature I have read has been showing basically miraculous recoveries in animal models.

It is inevitable because of the potential money to be made. I am sure they will solve the major problems. The big question is when.