Hang on, if you're off balance, it means your posture is wrong. Without posture, you can't have balance.
Which is why you train to either maintain, or regain posture!!
These things should have NO effect on your posture. as to the effectiveness of PPs, why not ask certain members of this board who work as LEOs and use PPs everyday.
I'm not sure what you are trying to say here. Let me say this, If you maintain correct and functional posture, then the angles and directions of each point will be presented to you, by the reaction to your strikes by your opponent.
It's not about fixating on points, it's about targeting. And you are targeting areas that are as big as an eye.
All of those things cause pain. Whilst pain can be a good thing, if your technique relies on pain to succeed, then it is doomed to fail. PPs do not neccessarily cause pain, what they do cause is anatomical weakness in areas that can and do have an effect on the postural integrity of your opponent, there by negating his ability to continue fighting effectively.
Can you punch someone in the nose or on the chin or smack them in the ear? If you can then you can target nerve points.
How simple do you want it? Hit nerve points effectively and people fall down. The most important part of hitting nerve points effectively is to maintain postural integrity.
That is another subject entirely.
--Dave