1) Spock talking about pon farr seemed out of character to me (one of only 2 times that I noticed that the character wasn't living up to his established history; the other was his attitude in "That Which Survives".
I have my own pet theory/rationalization about Spock's behavior in this ep. If you look at the order in which the episodes originally aired, "Cloud Minders" comes directly after "Requiem for Methuselah" and "The Way to Eden," both episodes in which Spock's aloof, reserved attitude is challenged to some degree. "Requiem" ends with McCoy giving Spock a hard time about his inability to understand love. And in "Eden" Spock seems distinctly intrigued by the space hippies and their groovy, less straight-laced ways.
Maybe Spock was having second thoughts about completely repressing his emotions by the time they got to Stratos and was perhaps making an effort to loosen up a bit more, which made him more receptive to Droxine's advances than he might ordinarily be . . . even if this was just a temporary phase.
Mind you, I don't believe for a moment that this was intentional; TOS didn't do multi-episode character arcs. But the timing is a happy accident. I like to think that Spock took McCoy's admonishment in "Requiem" to heart and was, however briefly, more open with Droxine as a result.