I don't think insulin bottles have latex. Latex allergies are too common. I'd look into trying a different type of insulin/syringe.
There's a LOT that can be done about reddness around infusion sets. IV3000, steel needle sets, skin barrier wipes, etc. I really hope they didn't just take him off the pump before trying that stuff. I would have quit in my first week of pumping if not for that.