I experimented with Sims 3 in VR awhile back with the Oculus DK1, using Tridef Ignition. I couldn't actually play the game because the UI was all messed up, but I could float around with the freecam which was really cool. With Tridef you had to set the scale yourself, like VorpX, so it was neat shifting them around so they looked like giants and then like tiny dolls/dollhouses. I couldn't really get the scale to ever seem normal though.
I can't afford a Vive or the necessary computer upgrade, but I do hope Sims comes to VR in some form eventually. However I really hope they do not simplify the game in any way to make it more "comfortable." I think playing just like normal, sitting down with just a mouse, would be perfect, with maybe a bit more depth to the freecam mode, but no change in the actual gameplay. I think making a separate game or pack for it would be a mistake, best to just tack it on as an afterthought, a neat mode that can be used by the few folks who happen to own the hardware, since I'm guessing even those who do play Sims and do have VR still will spend most of their time playing it with just a monitor and will only switch over every now and then.
As for this first-person mode, maybe somebody can get it to work with Tridef or VorpX or something (I messed with Sims 4 a bit with a mix of Tridef and Virtual Desktop with my DK2, but it was more like playing it on a 3d monitor so wasn't really VR), however it'd be FAR better to just use freecam mode. Being moved around without any control of the camera is barf city.