You can reset your skills after opening the Hall of Darkness. With 2 elemental portals open, that will be next.
Note that the full reset also means unlearning all skills, including those from rare or hard to find spell books.
I am confused what you mean by unlearning all skills, I did it last night and was able to retain all of my skills? Was that a bug?
Also, I can't reset any of the followers that come with the party, they will only talk to the "master".