Wanted to play GW2 on my Linux Laptop (Steam Proton is easier than setting up the original Launcher), also thought about buying a Steamdeck in the future. No, you cant lauch the 2 different Versions at the same time and based on a quick Google Search, most Multilaunch Tools (GW2Buddy, GW Multi-Launch, GW Launcher) dont seem to support Steam Login.

I think they moved all JPs to the weekly category, and left mini dungeons in the dailies. Also seems like the pool of minidungeons is only Spirit Vestibule, Vexas Lab or The long way around.