1) Sam can detect someone who is Goa'uld or Tok'ra, yes? (That whole "was a host" thing.) Is it established how far that effect works? Does she have to be within touching distance? I'm guessing a mile away would be no good, but would a room away — or from a corridor outside a room — be at all plausible?
2) I've read stories in which people are unwillingly implanted with Goa'uld. Has that ever happened onscreen? If so, or even in otherwise-canon-faithful fanon, would there be one host and another, unhosted Goa'uld in, like, a suitcase or something? Would a host instead be abandoned by a Goa'uld looking to move into a better-placed host? Specifically around the end of season 7 of SG-1, the start of season 8 of SG-1, and the start of SGA, would the Trust be likely to be involved in such an action, and if so, how would that influence the other elements of this topic? Basically, say you have someone being cornered and threatened with implantation — what's most likely, and what just wouldn't happen?