This seems to be a very fair critique, something that I would note most specifically about Ran is that her belief in the supernatural is extremely common for the Japanese people. So while it can be a downfall, please remember it is pretty common place and her belief in the supernatural usually doesn't affect her in dangerous situations.
I would like to ask though why you think he's cold hearted. Yes, he does tend to brush off girls that like him but don't you think it's rather that he's think headed than cold hearted? In previous episodes we see that a girl on his soccer team liked him, in that case his eyes were soo set on Ran, he didn't notice her affections. I think this is the case with the many little girls who like him. He's just oblivious because he likes Ran. That's one member's opinion though.