I think PostBourgie's G.D. is probably correct to worry about Tracy Morgan's mental health. But because a lot of people in the entertainment industry don't seem entirely mentally healthy, either because their business or fame made them that way, or because that imbalance is also the source of their genius, I want to take this interrogation a little further. It seems to me that there are a number of possible truths of this particular situation:
1. Tracy Morgan is perfectly sane, and, as an extraordinarily good actor, has decided that insanity is profitable. What that says about his regard for us as an audience and our taste for madness (especially in a man of color) is a bit uncomfortable, of course. But he's healthy, we're healthy, it's just the interaction between us as consumers and him as a provider that's a bit messed up.
2. Tracy Morgan is somewhat mentally unhealthy, but doing comedy is a healthy outlet for him. In that case, his behavior may be unpredictable, but it's basically controlled. Tina Fey should be commended for providing him that outlet, and for finding a way to mine fairly consistent gold from it. As well as from Alec Baldwin. We might want to be careful that we don't become too invested in Morgan's crazy, especially if he finds a way to divest himself of it and decides he wants to go for it. No matter how much we might love his art, his right to manage his brain however he sees fit trumps our right to enjoy the fruits of it.
Which brings me to...
3. Tracy Morgan is deeply mentally ill. In which case, is it ethical for the folks at 30 Rock to remunerate him for a role that is directly based in that illness? Even if he wants to do it?
I genuinely don't have the answers to any of the questions posed by these scenarios. In an era of widespread reality television and characters who are based closely on actors' personalities, the problems of whether it is safe to use people who aren't entirely well for entertainment purposes--for them and for us--and whether it's ethical to do so are worth consideration.