I believe the DUI came shortly after he was cut, so I doubt that was a factor.
If you ask around the league, I think it'd be generally unanimous that Spencer Ware is currently considered a better talent than Christine Michael. Ware has morphed into one of the best dual-threat RBs in the NFL. His style would certainly be a nice fit here.
Personally, I thought he looked great in his first preseason here. There were multiple times in his rookie season where he was also activated ahead of Michael. Ultimately, Ware was a victim of the numbers game, and to be frank, the Seahawks had a lot invested in Michael at the time.