Ok, there seems to be a LOT of confusion and misinformation here, so let's go :
1/ V can be reflected without additional cost (if you have RT on). After all, every other characters are reflected (Jackie, any unamed NPC etc..), why not V model? You can have your character reflected by a very minimal change using a text editor (you'll find it easily if you google it).
But right now, if you carry someone (dead or unconscious) and look at a refllective surface, you will see the person you carry levitating in a weird position, but not yourself.
2/ If V were reflected, you would have nightmare. CDPR, most certainly because of time constraint, abandonned the idea to unify first and third person model, like for example in the last game I played kingdom come delivrance. They chose to make a first person only model, and the issue is that this thing is horrible if seen in third person, hence the absence of V in reflections.
3/ The 3rd person character animation is already here, as it is used by NPCs. If you pay attention, NPCs do everything you can do, even the special move when you crounch while sprinting and start sliding on the ground. So no, this is not the issue
4/ The reason you can see yourself in those mirrors is that those mirrors do not mirror your character. This is an easy cheat, where they produce V 3rd person model (the same you have in your inventory, and franckly, not much work as 3rd person models exist for EVERY other characters) in a pose. You do not REALLY look at your character reflection, just a copy in front of you, like an NPC.
5/ V looks down in every mirrors because that is what V does at the beginning of the corpo lifepath (there was a good reason then, as V was sick and felt beat down). They simply didn't take the time to make any other pose and kept this pose for every mirror encounter.
