How do Necro Nova Bombs work

I've just acquired Summon Minions and Death Nova fro the Kryta mission. I went outside town and took on Fire Imps with my new bombs. Summoning minions (level 8 ) I used Death Nova and walked around with this enchantment. I didn't notice any Fire Imps getting poisoned though - they're health bar never chaged that unsavoury yellow colour. What's going wrong?

Death nova u cast on allies and if they die all foes arround them get poisoned.

Fun thing to do:

Summon minion/s during a battle, cast nova on them - since they are guaranteed to die anyway, AND they are always near an enemy, let'em blow up too!

The idea is death nova your minions, if possible taste of death them to kill them where you want, and watch the enemies drop along with your minions.

The Death Nova + Taste of Death combo is really powerful with high death magic, and is a great way to reap in lots of energy and health at a specific time, while dishing out serious damage. I used that combo for a really long time, until I started using Bone Fiends instead of minions and horrors, since fiends rarely go into melee range. The combo also requires a lot of micro managing and click targetting since we can't target minions with hotkeys... but it's not that much more complicated than target healing.
The poisoning effect only happens when they blow up. That's why Taste of Death can help, since it creates a trigger switch for setting off the bomb. Unfortunately, ToD isn't that precise if one has a lot of minions running around... as a N/Mo, I'd raise minions/horrors, use Heal Area to keep them alive, and cast Death Nova on each of them before heading into the next conflict. This usually meant I was pulling up the rear, but that's ok... when I got there, I'd target an enemy within a cluster or mob, sending in the minions, and then trigger ToD to set at least one of them off. It's really effective if used after an Ele's AoE attack, to bring down any remaining stragglers. Remember, minions won't rush in to attack unless or until you attack something, or something attacks you... otherwise they'll just stand around you and wait for the signal. With minions, I prefer for them to follow in after the initial frontline attack, or for them to block enemies that do an end run around the frontline toward us in the back. A little off-topic, but worth mentioning.

Oh I have to target the minions?! I was casting it while an enemy was selected and it was obviously being cast on me by default - I assumed it was a global state. I look forwards to blowing things up!

Regards these Minion Bombs, anyone tried them on the route to Droknar? I've taken a brief glimpse into that area before and no it's pretty rough. The idea of sending in a half dozen exploders should deala lot of damage and leave enough corpses for the next bunch of exploders. Yes? No? Or does it just get so thick with mobs in there you haven't time to amass a Bomb Brigade?

Is there a hotkey method to target/cycle through corpses? What about cycling thru minions, other than "v" to grab the nearest?

There's no such short-key to my knowledge. This was very apparent when playing a healer and trying to select NPC allies was a nightmare.