Everyone has their preference with regard to textbooks.
Personally, for mathematical methods texts, I prefer:
Essential Mathematics for Economic Analysis by Sydsaeter and Hammond
Further Mathematics for Economic Analysis by Sydsaeter and Hammond
For a good guide to matrix algebra:
Matrix Algebra by Abadir and Magnus
For a good book on statistics:
Statistical Inference by Casella and Berger
Introduction to Mathematical Statistics by Hogg and Craig (Not personally used but have heard excellent things on it.)
Also, none of us can say how mathematical VU Amsterdam is. None of us have been there. However, if you're capable of working through the textbooks I've listed above, then you're more than capable of handling an MSc Economics programme.