You were right, shins should probably be rebuilt. Foam is amazing. Honestly your chest looks pretty good, a piece that will make your suit probably feel better would be the ab-wrap for your stomach and would fill that negative space you are probably thinking about. I would suggest making it out of 4-6mm foam.
The arms look pretty good to me and the helmet as well. Maybe consider looking at doing the thighs out of foam before doing anything with the chest(cuz honestly the chest looks dang good imo). they(thighs) look good, but it looks like they might be missing some details.
I would be proud of the build but I definitly understand wanting to rebuild pieces. I think it's something all of do no matter how good it is
