I think he can handle hot tempered, he has a grandfather who er...well...is exactly like his father just more physical in a calm way then what Tamaki is. XD
http://youtu.be/83giYG9q2u4?t=13m30s
As you can see here (just watch how easily he throws his future son-in-law into that wall and then stands on him and then we have the 'hes a ladies man huh'? Anger which he starts to have but calms down and then theres the part later on when he is at the supermarket with the Host Club and basically yells at Tamaki that he is his enemy) so yes, Ry can handle him, it isn't like he hasn't seen a argument between Tamaki and Ranka before so she shouldn't be too bad surely. XD
If anyone can handle hot tempered it is Ry...granted, different sort of hot temperedness but still. XD