I think the examples could be spell check/typos and the last example, looks to me like the teacher conflated a couple of phrases that then didn't make sense.
In my experience, class/subject teachers write reports, they are checked by a colleague and then checked again. It's not foolproof though and we do all make mistakes, however hard we try not to. I don't think there is an excuse for 'diffrent' though and when I typed it, it auto corrected.
There's a school of thought that thinks spelling and grammar are more or less irrelevant in this day and age. I don't subscribe to it and find it very irritating when text is written with little or no punctuation, paragraphing and poor spelling.
I don't think that any report should be sent out with sufficient errors to make the reader focus more on those than the content. I often, in my head, correct spelling, grammar and syntax in official letters and I did point out to House of Fraser that their very large sign saying 'Homewears' should have read 'Homewares.' They agreed but have not changed it.
Maybe the OP could say how pleased they are with the content of the report, but as they would like to keep it for the future , would it be possible to correct some of the errors.
Yes, teachers are human, but if the errors are multiple, I can quite see how parents can be irritated.