To what extent is a Muslim supposed to hate non Muslims?

Answer

We are not commanded to hate anyone, not even the kuffaar. The kuffaar are in need of Da'wat to save them from everlasting Jahannam. We hate their misdeeds and evil just as we hate the misdeeds of Muslims. We should not despise even the kuffaar. No one knows who will leave this world with Imaan.

However, it never means that we should compromise any aspect of Islam to please and bootlick the kuffaar. Befriending them is haraam. Abstention from friendship does not mean that we hate them.

Not hating them means that we should not harm them, have no malice for them and not to despise them. But it never means the mullock which today's bootlicking molvis propagate. Their concept means to bootlick the kuffaar, participate in their kufr interfaith plots, mingling with them, bringing them into the Musaajid, and in general to dilute the Shariah to accommodate the kuffaar. Such an attitude is haraam.