v1k1ng: Does the ring of influence still give you +3persuasion and haggle even if you don't meet the cha requirement for such an increasing level of those skills? I plan to take only child as a background which sets penalty to cha, hence my curiosity.
The short answer to your question is: no, not right away.
Those three ranks will be there, but unavailable to your PC until such time as you put enough points into CH to uncover them. For each new level, you'll need a CH of 6, 9, and 12 (and 15 if you've already invested a point in CH yourself); with that background, 16 is as high as you can go anyway. The ring itself provides a +3 CH bonus (as well as +3 to BE) but it doesn't increase your maximum beyond racial or background limits.
This works the same, btw, with the other stats as well. If you wear a DX-boosting item (or cast Agility of Fire) and invest heavily in Melee and Dodge, those extra ranks will disappear when your bonus DX does, only to reappear the next time you wear that item or cast that spell. Similarly, half-ogre techies get around their IN limitations by drinking potions of IN when they're ready to invest points in the upper levels of a tech college, and again when they want to craft those items.