don't half *** it.. blast it.. can rent the compressor and all for not too much then start from there.. prep everything for paint properly.. you'll be a lot happier in the end.
agree, this would be best option, then epoxy, all imperfections can be filled with rage filler, sand and feather, 2k surfacer, sand with 320 and topcoat.
myself, I degrease, then hit surface rust with wire wheel, scuff sand with 220, shoot epoxy, let cure, topcoat. done ! small imperfections don't bother me.