1. I don't think the total number of school days per year is to increase. The article doesn't say that. It says that the longest break with no school will be reduced from 6 to 4.5 weeks.
2. Yes, it is not super clear. The idea is that there are 5 terms. Between most of them will be a 2-week break. Except for the summer break, which will be longer (4.5 weeks), but shorter than the present summer break.
Student or Learner