I actually haven't had too many problems versus Raiden when playing as Shang. Granted, it's a very, very, very annoying fight, but it's winnable.
My biggest problems with Shang are against rush down characters like Reptile, Cage, etc. Once one of these characters gets in on you it's very difficult to get out of it with Shang because he doesn't have any fast wake up attacks that knock the opponent back off of you, and even worse is that Cage's combos are so quick that even if you block a string it's tough to start some kind of combo with Shang beause his starters are slower than Cage's (granted, this is online, I haven't really tested this out offline). Obviously the game with Shang is to keep the opponent off of you and juggle them all day with his fire skulls, but it's definitely not that simple. You have to be good at predicting your opponent with Shang because he doesn't have some of the other tools that are available to everyone else in the game (namely a really good wakeup attack to relieve incoming pressure).
All that being said, I think Shang can definitely handle anyone in the game and I don't think there's a matchup for him that the opponent has a heavy advantage. He may be at a slight disadavantage with some matchups, but never a big one. I think one of the biggest reasons for this too is the fact that his combos can't be broken because it's all projectiles (minus the 2 or 3 hit starter), your opponent just has to sit back and enjoy the ride...which is so very satisfying to watch.
My biggest problems with Shang are against rush down characters like Reptile, Cage, etc. Once one of these characters gets in on you it's very difficult to get out of it with Shang because he doesn't have any fast wake up attacks that knock the opponent back off of you, and even worse is that Cage's combos are so quick that even if you block a string it's tough to start some kind of combo with Shang beause his starters are slower than Cage's (granted, this is online, I haven't really tested this out offline). Obviously the game with Shang is to keep the opponent off of you and juggle them all day with his fire skulls, but it's definitely not that simple. You have to be good at predicting your opponent with Shang because he doesn't have some of the other tools that are available to everyone else in the game (namely a really good wakeup attack to relieve incoming pressure).
All that being said, I think Shang can definitely handle anyone in the game and I don't think there's a matchup for him that the opponent has a heavy advantage. He may be at a slight disadavantage with some matchups, but never a big one. I think one of the biggest reasons for this too is the fact that his combos can't be broken because it's all projectiles (minus the 2 or 3 hit starter), your opponent just has to sit back and enjoy the ride...which is so very satisfying to watch.