Ah, yeah, was there any particular reason you were using LMDE? Because I'm not sure what parts of systemd it uses (especially back then), but I always just edited /etc/systemd/logind.conf to have HandleLidSwitch=ignore and have had zero issues. Pretty sure there is a gnome GUI for changing this same setting, gnome-tweaks.
I would assume the bad WiFi support was due to it being Debian and Debian being notoriously behind in terms of updates for the sake of stability.