I have to agree with the original post's basic point:
When did Hannelore become so gullible?
Ever since her pregnancy "scare" I've been wondering where and when she lost her common sense. Possibly the most interesting character has become nothing more than panic-induced comic relief.
I was about to say, "Yeah, things have been going downhill since the pregnancy scare," but then I looked at all of the comics between then and the Worry Hat arc, and I like Hanners in most of them. (Especially the Mr. Clean one and the dream sequence arc.) I felt that some were kind of "eh," but that nothing was over-the-top; she doesn't especially seem to lack common sense in most of them. (Any more so than she ever did.)
I just haven't been enjoying the Worry Hat arc too much. There have been enough "Hanners worrying over nothing" strips already, so new strips with that theme feel worn out, and the whole thing seemed predictable. Hanners freaking out about blood to the point where she throws out anything with a bloodstain on it is over-the-top even for her character. And as someone pointed out in the WCT thread, Tai is pulling a Faye in that Faye tried to frighten new Coffee of Doom employees with stories about giant coffee spiders (and succeeded with Raven). Gullibility is one of Raven's characteristics, not Hanners's.
Maybe Jeph is morphing Hanners into Raven, since we never see Raven anymore.
I think the visit from her mother may have accelerated her self-infantilism. While I do think the current Hannelore who can't cope with a minor scalp laceration and who goes catatonic when informed of the reason she shouldn't play drums in a mid-thigh skirt is hyper cute, on the verge of being kawai, I'd like to see her make some breakthroughs in coping with her OCD with her therapist, like Faye is.
She has made some breakthroughs in coping with her OCD. She's made friends and spends time with them instead of spending all of her time cleaning. In one strip, Marten asked her to have dinner with him and some others, and at first she answered, "No, I have to clean." Then she changed her mind because she remembered that her therapist told her that she shouldn't let her OCD get in the way of her socializing.