I am not sure if it's totally wrong, but I do know it's one heck of an ugly sentence.
The correct way to say that sentence would be "Children burning out from overextending themselves at school is far more worrying than anything the teachers might have to say about their grades."
I guess this is new wave journalism. "be" in this case is simply bad writing because the word is unnecessary even if it isn't wrong.
Just for more information "Children burning out from overextending themselves at school is far more worrying than might be anything the teachers have to say about their grades."
The above sentence I have written myself and I am not confident in it's validity as the construction "than might be" is fairly new to me but I have encountered it in many other texts as follows:
"One of the more intriguing aspects of the plagues of wrath is that the survival rate appear to be higher than might be expected."
"We thought it safer to err on our own side of the question, and to ask for more than perhaps under all circumstances we expected to obtain, rather than to limit our demands to less than might be intended by our Government."
I am just wondering as to the proper usage of such constructions as there does not seem to be much information available about it.
It's a valid construct indeed. The meaning, I think, is clear to you. If there's any doubt about it, though, you could put 'might be' at the end of the sentence and have it mean the same as it does now.
While we're at it, know that you'll come across other sentences like:
"None of those can you take concurrently with this one."
Hope this helps!
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