I have an idea regarding the current decision for spellcasting to be cancelled when a character moves. My DoM are currently only around level 23, so I am not the expert on playing the classes/jobs in question, but I came up with an idea while playing yesterday which I thought I'd share, and see if others agree.
My proposed solution: When a player chooses a spell to cast, they are able to move without interruption, but until the spell is finished casting, they are only able to walk, not run. Essentially, mobility while casting is limited to walking slowly.
To me, this makes sense from a lore standpoint too (reciting encantations would be difficult while sprinting, but while walking slowly it wouldn't be too difficult). This would also allow mages to do tasks such as dodge environmental obstacles, and would eliminate the problems with player inertia and /facetarget as well. Like I said, I don't have much experience with the DoM classes though, so I'm happy to hear from other players why my idea would not work!
At the moment, this decision has caused quite a few players to be upset, and has even caused a response by Yoshi-P himself on the matter. A large part of Yoshi-P's reasoning for eliminating casting while moving was for PvP, where mages would have an unfair advantage by keeping melee classes at a distance while bombarding them with magic. With my proposed change, the slower movement speed would not create this advantage, as melee classes could easily close in on their opponents while running. At the same time, DoM players can be satisfied knowing that they aren't rooted to the ground, and that they can still try and outmaneuver their opponents, albeit slowly.
Thanks for your time. :)