Thanks for the assistance, everyone! I finally seem to have it fixed (watch it start breaking again lol)
I'd verified files several times, but about the 10th time I did so, it complained that 1 pigg was corrupt. I deleted it, redownloaded it, and verify showed another bad pigg. Then, I deleted ALL the piggs, redownloaded them AGAIN, and machine blue screened. Each time I opened the launcher, my machine froze. I deleted 1 pigg that was 0 bytes, and launcher allowed me to re-download, again. Been good for several days, now 🙂
Short version: Re-verify files more than once. 🙂