The problem I have with Resident Evil characters, aside from the fact that other Capcom reps such as Megaman and Ryu, or even Viewtiful Joe, are more deserving, is that they rely on elements simply too mature-rated for Smash Bros.
Your moveset is a dead giveaway to my point, as you listed Leon using weapons such as a shotgun, pistol and knife, all of which fall under the "Real World" Weapons category. In otherwords, they're weapons commonly used in street violence in reality that their inclusion would up the ratings due to their association to real world violence. As stated in his journal, Mr. Sakurai doesn't want that, and his decision to remove all of Snake's guns and knives, with explosives as a replacement, directly reflects this wish. The problem with Resident Evil characters in this case is that they rely on those "Real World" Weapons in their games, and so most of the potential for their moveset would be lost for ratings purposes. They could rely on explosives like Snake, but then that could have potential of running into them being too similar to Snake, or even a Snake clone.
Second, the whole concept of Resident Evil is around the horror element, whether it's zombies or insane villagers. Again, these elements would raise the ratings and make the game potentially too scary for younger players. Mr. Sakurai is aiming Brawl for as wide of a target range as possible, including relatively young players.
In my honest opinion, I see Resident Evil just having too many ratings issues to be really worth including into Smash Bros, especially when there are better alternatives such as those mentioned before. Snake was included because his creator, Mr. Kojima, is a friend of Mr. Sakurai and practically begged for Snake to be included, I don't quite see that happeneing with the RE creator.