There's a problem with starlifting that I hadn't really thought of before but becomes a serious issue when you consider the role of metals wrt a star's characteristics. A typical star with an average level of metallicity relies on the metals to absorb the X-rays and whatnot put out by the fusion in order to turn that energy into a more even black body spectrum. Without those metals a star turns into something fairly degenerate (subdwarfs) because most of the energy from fusion which would keep the star hot ends up being radiated away quickly as UV light.
Pretty much if you try to strip the metal out of your star you can end up turning it into something which no longer supports life and which no longer even produces enough usable energy to power your civilization. On the other hand I'm pretty sure that the masses of the terrestrial planets not including Earth are still more than large enough to create a dyson swarm that would saturate the sun's output anyway (particularly when you consider the lossiness of energy conversion and the machines using the energy).
I mean if Mercury + Venus + Mars = roughly earth's mass, and earth has enough mass to build a billion times its own surface area in habitats, and if the sun produces a billion times as much energy as falls on earth, we could find rather counterintuitively that we end up energy limited long before we run into mass limits, especially with the much higher base energy requirements of habitats relative to a planet that's held together entirely by its own gravity.