There's no suspicion because there's nothing to warrant it: he knows the cats were trying to do something, and he has no reason to believe that Usagi and the others were in on it after he calmed down and was given the opportunity to leave, rather than the promise being taken advantage of. And there's no irritation because his attention is on his latest predicament while the cats are away, which would be the source of his irritation or anger (out of sight, out of mind, as it were).
However, as far as the general suggestion is concerned, I can see the sense of it. I'll see if I can find a place to show Ranma's irritation/anger with what the cats had done, since his thoughts about it a bit later don't really express anything like that. If I decide to do something with that one particular paragraph, I may find a spot thereabouts, if not before or after it.
Man, setting up the for final stretch is tough. :O