Not fair to go after anyone that is not also asexual, simply a recipe for disappointment, but it sounds like you know this, so fair enough.
>once you become good friends and develop a strong sense of trust, you can let her know you like her (or that you may like girls) and see what happens
It's pretty manipulative to make friends with someone just because you want to get in their pants. Granted people do this all the time, but it sounds worse when you suggest exploiting someone's trust for your own devices.
>if you think she's 'hetero,' don't let that stop you.
>i've 'converted' (more like awakened them to explore other possibilities) more than my fair share of women
OP personally I'd ignore this, horrible advice. Please do listen to and respect people's boundaries, if this girl tells you she is heterosexual or otherwise not interested in a relationship, don't consider the matter still open for consideration, take their word for it and move on. It's really shitty to ignore another persons choices and boundaries, if they change their minds later on fine but until that point you have no place considering them fair game/making any move other than up and up friendship.