These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
What Do You Mean, It's Not Symbolic?: Arguably the Animal Motif of the condor. The idea established at the end seems to be the other kids' souls were going to Bug because he's the condor and "eats death". Whether that's sufficient is up to you.
The slash marks in Bug's shirt are diagonal down the shoulder blades, exactly where a set of angel wings would be.