Mint's been good to me over those years and i'd like to share my experience of optimizing KDE for Wine gaming.
Firts iwas a happy camper in gnome2 but i had to change and Gnome3/Mate where inadequate, Lxde/Openbox were a tad depleted with features.
Kde was my DE replacement, i love its configurability, stability and its great apps (dolphin, okular are great).
My only pb : Wine gaming performance was lagging behind Gnome2's... and pretty badly (40% less in my tests).
I tried first to disable Kwin's effects but it still lagged so i took a more extreme turn : installing openbox gave me an option to boot Kde with Openbox (replcing kwin).
The performance is now in par with Gnome2's and i can still enjoy Kde + get some effects thanks to xcompmgr...