Although late in the process, I would have advised scraping rather than carving. A gooseneck scraper is the ideal tool for working within the concave areas of a carve such as this to cut down high areas.
Bondo or equivalent products are good products if used sparingly and for good reason rather than as a rule.
Primer coats are also very useful and cheap ways of checking your substrate's curves or flatness. One trick is to lay down a thin mist coat of black primer or even colour coat over the raw wood (hold the can further away than you would usually do) to show low and high spots as you sand the carve. A hard flat sanding block carries this out on the flat areas (of course) whilst a bendier material (such as a school eraser or a cork block) works within the carve as it conforms to the shape. After this you need to lay down a consistent and solid primer coat.
Primer is an essential intermediary coat between the substrate and the colour coats. Primer grips to wood and paint grips to primer. Paint does not grip wood well. I would not regard it as optional in any way, shape or form. At the very least, it provides an opaque basecoat to work from. Most importantly it ensures top coat adhesion and makes the final finish durable. Primer provides a barrier between relatively solvent-heavy colour coats and the wood, which would otherwise absorb the solvents instead of letting them dissipate outwards into the atmosphere. Meanwhile, your badly cured paint falls off.
I would stop with the paintwork and go back to ensuring that your wood is perfectly even. You can't fix that in the mix later and this is what will cause you to kick yourself more than anything when the build is complete.