As to the typos...
Back in the days I worked for a small publishing company.
It really depends on the exact arrangement in the contract for issuing a book.
Sometimes you get the forms ready to be used in offset, sometimes you get the files in *.cdr and you prepare the forms, sometimes you get a word document, that you use to create the *.cdr, sometimes the author chooses to use a separate company for proof-reading and formatting the initial document etc.
In general, we strongly encouraged the authors to use our services for proof-reading, even though the profit margin for this service was not that high, because it is our name that gets printed there as well and we did not wish that the company is associated with low-quality product.
If typos are really that common in SAP Press books, then I am genuinely surprised that they don't try to enforce higher standards, because, as a well-know company, they could say to the author: 'Give us the permission to proof-read the content and fix the typing errors, otherwise we would not publish it.'
I could be wrong and it is possible this is not how business operates in the rest of Europe, but good reputation is also an asset, so investing in it makes sense to me.