I more or less agree with your interpretation but it seems to me that the crux of any disagreement you have with Alicorn may well be over your respective defintions of 'straight' for males and females rather than a disagreement over the prevalence of certain behaviours.

Examples of behaviours that are quite common between girls I consider 'straight' but I would consider an indication of homosexuality in (western/anglo-american) males: holding hands; kissing on the lips; sharing a bed; overtly sexual dancing; commenting on the sexual attractiveness of other females. Would you consider any of these behaviours evidence that your girlfriend is not straight? Would Alicorn consider any of them evidence that a girl is not straight? That's where I think some clarification is needed.