If you're in TOV content, most of it is already undead, so you don't have to use the nuke to change it. Don't need any special hotkey for it, just the Scent AA (which automatically does a slow as well). This slow is not as good as your spell version, from much lower level. But I don't ever bother memming the spell, since if you focus on DPS mobs don't get to do so much damage before they die.
I don't use a swarm hotkey either. Binding together multiple swarms is a bad idea. One swarm needs to finish summoning pets before the next will work correctly, and the only swarm that does much damage is the spell swarm. The others are very light DPS and light tankage. If you do use AA swarm pets, it is better to weave them into global cooldown between spell casts. I hardly ever use them even then.