the thing is, game engine as it is aimed at showing us lots of stuff at the horizon
which adds an immense immersion and exploration part (e.g. you travel, see something on the horizon, wanna go and check it out)
so, honestly im not sure it its worth bringing F3 into iso, therefore removing this immersion part
on the other hand, interface itself needs serious overhaul of course (e.g., health compass etc done in fallout-style)
also, cameras are f*ked up seriously, they reset after sitting on the chairs or exiting VATS, what would be nice is like 3-4 preset cameras, from 1st person view to good overshoulder views flowing into full 3rd person view
to be honest, as a purist myself (yeah yeah) I would vote for F3 with:
3-4 polished camera presets from 1st person to overshoulder to 3rd person
fully turn-based combat
lots of polishes like UI, char animations, weather, quests, F1&F2 weapons items and armor, tougher enemies (killing supermuts with 10mm pistol wtf) etc etc