>>Wasn't there a "X-Men Origins: Magneto" film in the works at one point?

Yeah...and they changed the Magneto origin story into "X-Men: First Class" because the solo Wolvie flick got such mixed reviews (despite doing well at the box office).
They didn't want to risk making a solo Magneto film at that point. So, "First Class" and the new "Wolverine" flick were intended to be the redemption films for both the
X and Logan franchises (from a critical standpoint).