Even as purely an energy collector, it's ridiculous. Looking for it as an explanation is even more ridiculous.
Taking your assumptions for granted, yes, but you rather overestimated the mass required.
Hey, look, we spent all our resources and billions upon billions upon billions of tons of raw material - 2.83×10^17 square kilometers of surface area alone, equivalent to millions of planets or thousands of suns worth of material, more than everything available in the solar system around such a star
The original Dyson sphere posited using many independently orbiting solar collectors, not a true continuous shell. At your suggested area, simple solar cells (mostly aluminum or an oxide with thin film silicon cells) forming panels 1mm thick would require a mass of 8.5x10^20 kilograms - a bit over 1% of Luna's mass. If you pardon the sci-fi reference, this page gives an overview of the classic Dyson "sphere" and some hypothetical variants.
Obviously, shifting to lighter sub-millimeter foils like solar sails both reduces mass requirements further and gives the individual swarm elements maneuverability. The latter would allow stabilization of the collectors against gravitational influences found elsewhere in the system, like all the planets you didn't need to disassemble.
(At least not disassembled for the system's power plant. There are a lot of interesting things to do with spare planets once you have the full power of a star handy and a demonstrated ability to mine and process lunar-scale masses into engineered structures.)
the star inside starts acting funny from not being able to radiate as it might normally,
The star's going to radiate almost normally, it just added an extra step in the process: first its light warms the solar collection swarm (to about 300K for a low-albedo collector at 1AU from a G2V star), and then the collectors' temperature stabilizes by radiating from its back side. Minus the energy diverted by the solar collection process, the star's power still get into deep space but using a 2AU diameter radiator while the low albedo means you won't reflect too much back at the star.
The stellar surface might warm up a bit from reflection and the 300K radiator engulfing it, but it's sitting at an advantageous end of the black body curve: radiated power follows the fourth power of temperature. A little bump in surface power will be rapidly reach equilibrium.