My thoughts on the subject are quite simple.
I see nothing wrong with someone whose rich enjoying their wealth and success. Charlie Sheen likes to party. The big issue in his case though is one of taking the excess too far, which keeps him bouncing in and our of various kinds of rehab. It's sort of like how a lot of people can drink and go on benders, or how people like sex and might do something excessive like an orgy once in a while, the problem is that he does it to the point of self destruction.
That said, his personal self-control issues aren't a big deal as far as the show goes as long as he's capable of doing his job. The rest is between him and law enforcement if such things come up wherever he happens to be, and if he wrecks himself doing this stuff, well, it's not like nobody warned him.
Without knowing more about the writer, I can't say who is right and who is wrong. However it is noteworthy that a lot of what Charlie Sheen says is right on the money. We're dealing with a very typical sitcom in the vein of "My Two Dads", with little that's exceptional about it except for Charlie Sheen. Love it or hate it, he makes that show, and he's made the network ridiculous amounts of money, and could probably make them even more.
That said, while I can see a conflict like this boiling over into the public when someone like Charlie Sheen can't win quietly in the bureaucracy he has to deal with, he has picked the timing for this badly. To be entirely honest "Two and a Half Men" might be a TV institution, but at the same time the kid is growing up/has grown up and won't be a "half man" much longer which is a big part of the humor. What's more with a near-decade run people are getting burned out with it. How much longer could this show last given it's needs? By pulling this right now, the already highest paid actor on TV might be shooting himself in the foot as far as finding other work.
That said, I don't know the guy. I can't say whether he's actually a nutbag or not. We don't know how this played out, and from a certain perspective I can see why he might "call" his bosses in public hoping to rally fans to do what he can't do in private. I also can't say much about his lifestyle, only what's been reported, for all I know he might not actually be a real problem case and simply be getting slammed publically again and again by people who want a sensationalized headline.
I'm not a huge Charlie Sheen fan, and rarely if ever watch the show, I just think people are jumping the gun on both the pro and anti- Sheen side. Right now the only part of it I can say is really "dumb" is his timing in when he decided to pick this fight. The age of the show (and the age of the kid) making the pressure fairly weak.