Wow, that's a really interesting devil fruit!

Well, it works.

I'm assuming you'd have the hornets do the fighting then..?

If you can think of good techniques to use with the bees, you should be fine.

The Haki on the stingers, well, later on when the crew learns Haki, sure, but it wouldn't be the strongest Haki around. Unless you only have one strong coat of Haki appear on one specific bee's stinger while the others would be regular. Or perhaps you could switch between all stingers having decent Haki or just one of them having strong Haki.

Well, I'm adding ya to the list for now, though, since you're interested and I don't really see much that could be wrong with this devil fruit.

That leaves only one spot open!