I mean, large engineering projects for the greater good of humanity don't really seem like our thing as a species, but the answers to most of your questions are

I mean, large engineering projects for the greater good of humanity don't really seem like our thing as a species, but the answers to most of your questions are yes in theory. If you can surround a star with a Dyson Sphere/Swarm, you can do all kinds of things to it including concentrating all its energy into a beam to destroy a planet like the Earth in seconds (though you can't blow it apart like in Star Wars that easily). There's a youtube channel dedicated to this kind of stuff called "Science and Futurism with Isaac Arthur".