Personally, I really like the idea behind the MS buff on Q, it brings her back around as a kiting mage. What concerns me, though, is the sheer amount of damage she is losing here. The current changes seem to be net balanced with each other. However, there's another factor in play here: the removal of dfg. Riot said ahri would get compensated for DFG's removal, but all I see are compensations for removal of the charm damage amp. Back in s3, they gutted her aoe damage so she could have the single-target E damage amp. Now that they're removing the amp and DFG, they could afford to be putting a lot more damage back into her kit, but they aren't.
Before 3.13, ahri's ult did 15 (+5% AP) more per hit than it does now. While it sounds small, over the course of three casts each hitting three targets, that amounts to 135 (+45% AP) total damage, though only 45 (+15%) per target. Assassin ahri doesn't really care for that damage since it's so spread out, but mage ahri does, and now that they're bringing back mage ahri, I think it's about time they revisit her ult damage. Either that or bump the ratio on foxfire to 45 or 50%, which would give her W single-target damage comparable to landing a charm+W on live, but considerably greater aoe damage. I feel at least one of these changes would be necessary to compensate for the massive loss of damage she'll be suffering here, and to ease her back into a mage playstyle after being an assassin for so long.