It was very useful to get feedback on my icons, as it made clear where the icons could be improved or where I should have made the concept come across better. For example, for icon 2 I got some comments on the text (font too plain; too white; too overpowering) and the border, but the idea behind the text and the border had been to mimic the Smoking kills warning you find on cigarette packets. As it turned out, that didn't work for everybody.
For icon 3 I got the very useful feedback from teragramm that Willow needed more color and brightening. So I changed that, and it improved the icon immensely (see icon 3') .
Icon 4 is the one that got me eliminated from the round. Several people commented on the icon having too much contrast, Angel's profile blending too much into the background, and the skin colouring being too dark / orange. So maybe I should have gone for one of the alternatives of this icon (lighter and less orange). Personally, to be honest I still prefer the version I submitted. I just think that the contrast and the flame-lit orange hue of Angel's face go best with the background image. Of course, maybe I should have gone with an altogether different background.
Update: I've added a third variant of 4, based on chasingdemons' good advice. It's probably still a bit too dark, but definitely a lot better than the rest.
In spite of everything, icon 4 did get to be Chosen One (mod's choice), and so did icon 3. Here are the pretty banners, made by hermionesparkle:
Let's see how far I'll get in round 11!
Many thanks to whoever nominated icon 4 for the No Rest For The Wicked awards! wicked_awards