Ummm, but godhood is not teachable. It is a (quote) "gift" meant for Morrigan.
Yes, and in the meeting with Morrigan Flemeth puts her hand over Morrigan's head and transfers something to her. Morrigan then says, "I... understand". That was the power Flemeth wanted to give Morrigan.
If Solas did not take anything editor notes would not mention "stealing" Flemeth's power.
Dev notes mean nothing. Besides, the power he stole could have been the eluvian.
Also, in the Trespasser he is much more powerful.
More powerful than what? Also, when we get to the top of the steps in the first elvhen tower, we see an explosion similar to the one at the conclave. That could have been Solas unlocking some elvhen artifact and gaining power that way.
He must have taken sth from Flemeth.
Maybe he just felt she was unworthy of carrying Mythal, and killed her to free Mythal's essence so it could return to her full spirit in the Crossroads.
He would not kill Flemeth for the Eluvians. He had access to them anyway (THe Masked Empire and Trespasser prove it).
Masked Empire proves he didn't have access to the eluvians, and Trespasser comes after Solas kills Flemeth.
Finally, Flemeth said that Mythal and her are one, like the heart is a part of one's body. Also, would not Abelas know that Mythal was in the Well? There is no hint that the woman from the well was Mythal and not some spirit servant or w/e ;//// ... So it is a very risky speculation.
Well who else would it be? There was only one spirit, and it as female. Now, it was a human woman, but the devs have since stated on Twitter or something that the model was supposed to be elven. They just threw in a human female because they thought the water filter would obscure her rounded ears.
Abelas knew little of Mythal. Flemeth even tells you that she doesn't care to reveal herself to anyone.
As for Flemeth being one with Mythal, that only means Flemeth carries a wisp of her, and Flemeth even describes it as a wisp. Mythal's full form was likely in the Well, reforming over the ages.
Solas states that his friend, the Spirit of Wisdom, might reform in the same location in the Fade some day, though it will likely be a different spirit. Mythal is probably doing this, but she had the Well of Sorrows to help her. So she likely returned in her full essence over time.