Using a high quality filler like evercoat rage. Etc.. Will work fine for you evercoat sands easily imp... Epoxy Spot prime when you can because filler will hold moisture and come back and bite you down the road
Here's one issue you will have with holes, Getting the filler to stay in the small holes will be a challange , you will be better off filling them with weld as well and skim coat them with filler . Also problem when filling holes with filler creates an entrance point for moisture to wick thru from the back where the tail of filler protrudes into the un accessible space .
Always make sure that you read the material data sheets for the primers fillers color and top coats you plan on using to make sure they are cross compatable or you will have problems .
This again will start the primer before filler. Or filler before primer debate,
I'm a filler before primer guy I feel the filler adheres to steal better then primer..
Again my
