They looked very much like full robots with all the sparks, empty eyes, twisted forms and other mechanical traits. So, it's safe to say Luffy didn't kill anybody.

Zoro and Sanji indeed only grew their hatred toward each other during the two years. I wonder how long it takes for Nami to knock their heads again like in the good old times when their fighting starts to bother the others.

I spied Perona in the preview. I was actually hoping to learn what happened to her. It would be poor writing to simply make her disappear as if she never existed despite the fact she, most likely, spent the same two years on Hawk Eyes' island pestering Zoro.