Looking for advice. Want to build a Duster to run on a budget.

....Welds don’t need to be covered with anything different than any other metal. It they’re structural just paint them, if it’s bodywork grind them smooth and paint them.
You suggested that someone that has never welded before should get a welder and learn,and there should be no filler in their project and if there is they are doing more harm than good. That is a compiltation of what you've been saying. I believe you also said that filler has no place in a car period.

How difficult is it to grind metal smooth enough to paint over as you are saying here ?