A bullet puller is fine if you realise you screwed up a powder charge after loading a bunch of rounds, especially if erred to the dangerous side. If I had loaded a box of .45s .2 grains lighter than what I intended, in most likelihood I'd just write it off as a lesson learned and fire away rather then going to the trouble of pulling bullets. I try to use powders that will overflow a case if doublecharged and visually inspect each case for proper levels prior to bullet seating, so overloads aren't much of a concern, at least for me.
I have no qualms tossing a round or two here and there that I've messed up. After all, components are relative cheap. I don't think I've ever tossed enough to equal the cost of a bullet puller, and that's after reloading since 1975. I've got maybe a box of "dummies" loaded over the years for setting up dies for various bullets shapes/weights.
As to changing dies, I don't see the issue. Really, how hard or time consuming is it? I mean, we've all got 24 hours a day to spend doing something, what's a couple of minutes spent changing dies? I size a box of cases (or two) , change die, flare, change die, and then seat/crimp. Once properly set, it doesn't change the seating, etc. I do, however, have issues with Lee lockrings and that useless "o-ring" setup. It's very easy to upset the adjustment. I converted all my Lee dies to lockscrew rings.