I've looked through the settings for you, but could not find anything that indicates that those things are possible. I only know how to stop SW from adding relations, by holding Ctrl while adding sketch lines.
Habib Ghalamkari wrote:
While drawing lines in sketches, is there any way to change a white flag relation to yellow?
No, there isn't. It's been submitted for voting on the SWW Top Ten List at least the last two years, but so far it hasn't happened.