Amen, keep the influence system. Indeed it started off sketchy somewhat, but it seems Obsidian managed to refine to the point which Starwars mentioned, comfortable. MotB especially so.
The influence system though as we know, is not something new Obsidian had been using. The first RPG I played that involves a degree of influence system would be the Star Ocean series. I really hope Obsidian takes some good pointers from the JRPG game I mentioned to further improve and refine the system.