I wasn't unsatisfied with the lack of details regarding her illness, and didn't want to give this impression. I tried to state it as a "fact". If there was something bothering me, it was the topic of exorsism, which wouldn't have been necessary in such an amount in this film. I realize that Requiem is based on actual events, and my statement may thus seem a bit absurd, but this leads to the second quote in your post. 
The "weakness" of the direction was imo, that Schmid chose this story about exorcism when he was actually concerned with something else (this is my impression). I think he wasn't interested in the screenplay as it was (see the fantastic movie-moments I refer to at the end of my review and which you also quote - they are not from the original screenplay), but used it as a way with dealing with personal issues that concerned himself. BUT, and that is my objection, he went into a direction where he tried to disguise this halfheartedly (or subconsciously?) and was still entangled in the story and the real life events. Thus we have a situation, where a filmmaker isn't making 100% the film he wants to make, but he also doesn't deal 100% with the material he has. 
There is imo no doubt about the talent of Schmid as a filmmaker. But I only hope that he will dare to express himself(!) more openly next time. 
If I draw the parallel to Zulawski and his Possession again. Zulawski went through 4 years of divorce which was like hell to him in the late 70s, and I think this lead to an extremely honest and powerful film. Schmid maybe hasn't the self-esteem yet, to expose himself in a similar way on the screen. 
But this is exactly what I expect from the best filmmakers. To present their ideas or their experiences as "honestly" as possible, (in their own ways of course). Examples for this are Hitchcock (Vertigo), Kubrick (Barry Lyndon), Chaplin (City Lights, Limelight), and of course Jean Eustache.
I mention all of these great directors, because I think Schmid has a lot of potential. He just needs to take more risks. I think this is something which still seperates him from other young german mavericks like Ulrich Khler. But his last film Lichter, and the fact that Requiem contains so far the best and most powerful moments in in his filmmaking career is already a sign that he is imo moving in the "right" direction. 

The camerawork was too much "to the point" for me very often. It didn't just register or show certain inner changes in the characters but pointed them out (that was my impression of course). I don't like it, when I realize what a character is thinking or going through in a certain moment because the film has been succesfull in hinting at it and making me complete the picture, only to get it accentuated at the end of such a moment through a close-up of a face or some other "obvious" device in the context of the film. I would even prefer a narrator who would recapitulate what was already shown than to get it "summed up" a second time through the visuals. 
Maybe it's just me, but I'm always disappointed when a film further develops the characters in a subtle way, and then again "shows" us the result at the end of such a sequence. I feel like the filmmaker hasn't enough faith in (or patience with)his audience in such situations. 

After reading it again, I think the sentence you quote is a bit of a mess (again, you must excuse my english). Maybe I should have formulated it something like this: 
"An affective camerawork tends often to point out obtrusevily the initially subtle characterizations of the protagonists making the direction appear insecure at some points and destroying the momentum and the rhythm of a scene. And there is also a problem that the images become interchangable and the direction seems clueless at other moments, when Schmid doesn't know if he should focus on what he wants to tell, or what the screenplay is about."
I liked the editing, but it didn't always go well with the camera in moments like these.

The screenplay was a bit of a real problem though. I didn't have problems with its concept (and its economy) per se, but the dialogue often kept bothering me. I thought it was at times unconvincing and forced, and didn't fit with the visual style Schmid tried to evoke. In the end this is of course the "fault" of the director (if things don't work he has to change them). Nevertheless the screenplay as it appeared to have been was the film's biggest weakness in my opinion. 

A short anecdote on this: 
A couple of weeks after I had seen the film, I met a friend who started talking about the film. She didn't like it, because she thought the screenplay was worth . The scenarist had been a fellow student of hers at university, and had written it in those times. She said that she was amazed that Hans-Christian Schmid had chosen it for his film. I thought her assesmet might have been a bit personal - due to the circumstances - but I agreed that while I liked the film, I also didn't like the screenplay. 

There are of course a lot of exploitive and sensationalist attempts at cashing in on the topic of exorcism, but I knew that "Requiem" would be beyond such concerns, considering Schmid's respectful and restrained approach to everything he had done before. 
I'm also glad that Schmid didn't go after religion and medicine in a direct way. In the context of the film and his filmmaking the attacks on it were very effective the way they were presented. 

Whow, just wanted to make a short reply, and have ended up writing a bit more. But I'll have to finish, as I need to get home.