I have yet to see a single undead destroyed by my turn undead. I would figure a level 4 cleric with 14 CHA could destroy a simple decrepit skeleton.
Also, to put into perspective the belief thing...
You cannot compare the average joe to a priest or bishop. Now then, there may be settings that allow these people who somehow transcend reality to believe in abstract concepts, but thats frankly very, very, very rare in ANY form, fantasy or not. Clerics are vessels of their own god's will and might. Simply put, most people who use superstitious signs don't have the kind of belief that a Priest has for his/her god. Its frankly stupid to think that someone tossing salt over their shoulder has more belief in that superstition than someone who has dedicated their entire LIFE to service of a single entity, and taken vows, oaths, and sworn to follow tenets of that one faith dutifully, forever.
Right, to continue.. *second edit*
I don't think that a priest who wakes every day and thinks "Oh, *yawn* another 5 miracles today" should keep their powers for long. These powers are granted through their god, and someone who stops frankly giving a damn will draw the ire of that god eventually. That example is a lack of belief, or rather, a lax in true belief and worship. I don't know where you get these level ones thinking people or things into existence, but i can say quite frankly, this is NOT the multiverse. This is one single demiplane. Stop drawing from abstract sources that are made for epic-level mass magic campagins that can have a simple commoner doing the most ridiculous of thing becase he believes he can, somehow with the fervent belief to make Cadderly himself look like an apostate. It's embarassing, I agree, that too few clerics actually RP their devotion and oaths to their gods, or even do the research for it, but it doesn't suddenly make this single thing better in any way.
I agree, it takes more to get the feat and its in itself not too powerful, its rather balanced with its requirements. Turn undead is limited though, mostly being used as a stepping stone to a Divine Might or Divine Shield use.