I don't mind having 4 players with 3 pads (and fourth one mapped onto keyboard). I kinda managed to tweak the SM3.9 4P so it forces 4P mode. Managed to get speedmods working and the arrows to not overlap. Removed screens that crash the game (my current version won't go into intro screen). Each player can have different speed mode, each player can have different difficulty. Only known problem is that rolls crash the game (just like the original StepMania). Sadly the source code doesn't want to build in my VS (will need to install older version to try it again later).
obviously screenshot with 640 x 480
I'm running it at 1920 x 1200 with no lag, stable FPS, timing issues normal (doing same Marv/Per ratio as on normal stepmania 3.9). No crashes on event mode. Was planning to run it on convention on 1920 x 1080 with hooked up 42" screen.
As for StepMania lan - oh god no, I remember running it once and it was requiring 24/7 maintenance. It was crashing every few songs.
So I assume that multiplayer functionality is not planned for main version StepMania. Any plans of doing a fork maybe after 5.0 final will be released?