Claudia going bad probably has nothing to do with Steve. None of this episode was required for that motive, and Artie is supposed to have created the evil by using the astrolabe.
Steve is dead. Since this is fantasy, he miraculously dead, the kind that stay's dead, despite near universal precedent. Jaime Murray will be back before Aaron Ashmore I think.
Sykes demise under the dhoti of death merely suggests that the warehouse team that filed it forgot to launder it first.
The continuing storyline shapes up to be bad Claudia plots and Mrs. Frederick finds out what Artie did and faces terrible jeopardy while the Knights Templar go after Artie because they know Artie did something since he has the astrolabe. There might be an artifact hunt in there but most likely every artifact pursuit will be a macguffin in the Bad Claudia, Mrs. Frederick in peril or Templars attack subplots.
Bad Claudia will be redeemed, Mrs. Frederick and
Artie will be saved and the Knights Templar will make nice in the end. Genelle will be in peril at least once, and useful at least once, but anything further is a crap shoot.