Very good point. I definitely don't want (in the extreme case) suicidal customers who expect me to fix their problems! The "market research" I've done has been extremely informal and involved me describing the idea to some academics (mainly master's/PhD candidates and a couple of freelancers). I've had mainly positive feedback on the idea -- from people who lean more towards your "just need a todo program" than "need serious help". I'll definitely put some thought into screening out the latter group, as neither I nor the PAs will be qualified to deal with them.