Jiraiya wins both scenarios.
-If Danzo uses KA on Jiraiya then Ma or Pa break him out
-Jiraiya survives Danzo's kunai attack after the first respawn with insignificant damage, then reacts easily to any further respawn attacks. Sensing Barrier or SM sensing makes it very easy to react. Matter of fact, I don't think Danzo would even land his first attack against three SM sensors.
-Baku gets Goemon'd
Yep, think I covered everything relevant.