When using the ruler designer I always end up with a ruler who has no family. He is the only member of his dynasty. Is there a way around this?
You can get around some of this by doing a little bit of save editing. Create a character using RD, name them something unique or be sure to note down there character id (We will call this Save A). Save that game. Start another game this and save it (Save B). Copy your RD character information from Save A into the character you wish to play in Save B replacing all but the character ID from Save B. As far as the characters from Save B are concerned that person is still the same person even if they've transformed, sex, ethnicity, religion and traits. Your family tree will also be intact.
I just used this method the other day to create a female RD Queen of Galacia who would still be in line to inherit the thrones of Leon and Castille should her brothers met an untimely end (They did.)