Kiss is a minor action, isn't it? And ... what else could it do with it's standart attack? 1d6+6 damage? Nah. Dominate is better.
The corrupting touch isn't anything great for a 9th level critter.
Also I disagree on 2 good rolls to land the kiss. More probably is 1 redicusly easy and one easy roll.
What I have forgot indeed is that most classes have abilities to push others away. So yes, it can be done. Still, it seems like an elite to me.
Can someone playtest the following:
succubus + 1 1st level kobold slinger against 5 1st level chars?
Give the glue bombs to the slingers, the ones that immobilize. Also remember that the kobold shifts as a minor action, i.e it can move near its devil master easier.
NOTE: Dwarves are tougher to move away from their master. Realistically the succubus couldn't know that the dwarf is a paladin, so probably it would target him for a kiss.
succubus +kobold = 500 XP.
You want more? Have the succubus know who the chars are and their motives and have it to be transformed to a "helpless" teenager girl that is adjusted to an evil kobold screaming for the heroes to help her. Then she kisses with combat advantage.