A university motivation letter should stay to one page and name the programme's actual modules. European admissions teams read for fit with the curriculum, not for the drama of the personal story.
A cover letter targets a specific job and its requirements. A motivation letter targets a programme or opportunity and focuses on your reasons and goals rather than your qualifications alone.
One page — around 400 to 600 words. European admissions teams generally expect brevity, and exceeding a stated limit counts against you.
No. The CV lists what you did. The motivation letter explains why it matters and where it is leading.