I just realized that the Archons would know that Parson is under a loyalty spell if they saw him... and, therefore, Charlie must know that Parson is under a loyalty spell (one that apparently goes beyond any of the natural thinkamancy we've seen described; it's unclear if that would even apply to Parson if he didn't have a separate spell.)
Sounds to me more like a substitute for obedience, there wasn't anything said about him not being able to double-cross Stanley (other than the threat of death), or using his own initiative to help Stanley.


From what Jillian says, killing Stanley would release Wanda from a loyalty spell (if she were under one) therefore I assume that Parson would be released from the spell and not disbanded if Stanley were to be killed.
Effectively, yes. Even if the spell stayed on Parson, Stanley would have difficulty giving orders, and there are not any standing orders right now anyway.