Kate Walsh is much too attractive and feminine to be a real lesbian. I think real homosexuality is physiological and is caused by hormone imbalances that are exacerbated by screwed-up childhoods. Many lesbian partners of real (i.e., butch) lesbians are straight women who are either nuts or in it for the money.
I would agree to some extent. Ever lesbian I know ( and I know quite a few since I play softball) had traumatic experiences with men, mainly sexually abused as girls.
As for Walsh, she is rumored to be on the D-Lo with Sara Martinez (Callie) from Greys.