Do the queens and kings of England marry within family?

Answer 1

They intermarried with other royal houses and noble houses in Europe. Especially with those of France and later Germany. So they would sometimes marry people who were distant relations.

They were not nearly as bad as the Habsburgs, who would marry nieces or first cousins constantly.

Answer 2

Oftentimes, yes. The reason being because they want to keep the bloodline going, so in order to do that, they mustn't outcross much.