So i've got the game working fine on Widows 10 in borderless windowed mode (fake fullscreen) alt-tabbing works and no crashes so far.
To do this you'll need:
Windowed Borderless Gaming: http://steamcommunity.com/groups/Window ... lessGaming
Your resolution settings set to windowed at your monitors resolution.
Launch PSO in windowed mode at you monitor's resolution.
Launch Windowed Borderless Gaming
Click the icon in the taskbar and choose add window.
Switch to PSO and press F3.
Windowed Borderless Gaming must be running when you play.