Earlier quoted context omitted.
Doing ten pages of mathematics a day is not realistic. Unless you already have been doing mathematics for years and are still relatively young. How about a paragraph per day ?
Depends on how dense your source material is. No matter your level of sophistication, if you are making it through ten pages a day, you should probably switch to harder material. The specific number doesn't matter too much, though. If you get through one page of dense math an hour, you are doing well.
But, I agree that the material can be boring and too basic. This is why I have always preferred Soviet books (they get directly to the point and don't address stuff you should know) vs. US books (that will go back to high-school level to bring you up to speed, after which you want to sleep). Generalisation, of course.