The -6 you get for "Meat' actions while in Full VR. (Granted, the example that was given was for merely perceiving the Meat World, but if perception is that bad I can imagine actually trying to move, although you'd have to disable the motor function over-rides first.)

As for being 'balanced', you've already let slip that your character has very low Physical stats but yet YOU think that rigging yourself will allow your character to run in the meat and you even used the word Tank.

You have also stated that the reason you are holding on to the idea that rigging your own body will provide extra IPs is because you do not want to 'waste' Essence on Wired Reflexes instead using Cyber to boost your pitiful Physical Stats. (I believe your exact words were that you didn't spend ANY BPs on Agility or Body.)

As for Feedback, well considering that it only becomes an issue while running in Hot Sim, AND that it is resisted with Biofeedback Filter + Willpower, I'm going to assume that it isn't going to be a huge problem since you had to have spent the BPs you saved on Physical Stats somewhere.

And Piloting Rolls for everyday activities, well I'm going to assume that your DM is going to gloss over them for the most part in order to keep the game from getting blogged down, and for that matter, the way I read the Rigging rules I'm not entirely sure that you would need to make Pilot Rolls and even if you did you'd be using your normal skills/stats so I don't see it as a huge hassle either.

A good reason it won't provide any extra initiative passes is that Drones have 3 initiative passes even when you aren't rigged into them(2 when you are rigged into them cold sim, and 3 hot sim as I understand it). Their mechanical bodies move extremely fast and are only slightly limited by physical reaction time(they don't have 4 initiative passes) and then are limited by the speed at which commands are sent at them(as shown in the difference between cold sim and hot sim riggers speeds)
Your body, unless it has Wired reflexes or Synaptic Boosters doesn't move faster than 1 initiative pass per combat turn, regardless of how cyberized your body is it is stuck at that speed, as such this is still a limiter on the number of initiative passes you have.

As for the down sides to rigging yourself, considering you've only got 1 initiative pass. As per the RAW you must spend that pass driving or risk a crash and take -2 while you try to control yourself from crashing(if you don't drive it doesn't cause you to use an action but you do take -2 on all actions). You shoot less often, because shooting as a rigger action is a complex action.

In tactical combat.
Page 160 "Drivers must spend at least one complex action each turn driving their vehicle or the vehicle goes out of control at the end of the combat turn"

If anything about what I said is blatantly wrong please correct me.