Should I use facebook to come out as trans to extended family and acquaintances?

I would wait to see how it goes with your parents Peter. It's going to take them some time to adjust to the idea and (hopefully) come to terms with your news and you don't want to do anything that will jeopardise progress. In fairness, it may be a lot more than 1-4 weeks. If you come out to everyone else on Facebook before they have had time to deal with their own feelings it could be counter-productive.

I'm not saying it's a bad idea, but don't be too quick to do it. Coming out to your parents/siblings is the priority and you can't predict how it will go or how long it will take.

 

I think it's real smart of you to come out to your family first, that would be my real concern with coming out on social media because I feel it's important to come out to your family in person. And I agree it's a great idea to wait a bit before coming out on Facebook. Honestly after all that it's up to you, will you be comfortable with all the people you're friends with on Facebook knowing? If you are, then I say go for it! And if there's like one or two people who you'd rather not know about it then im pretty sure you can set who you allow to see the post.
As for "dirtying" your family name I think that's ridiculous! While it's true and unfortunate that some people think like that about other peoples families, it just isn't right! You make the family even greater and I would be so proud to have you in my family. If people react really negatively to your post it gives you the opportunity to do some weeding out of any ignorant meanies in your friend list. If they can't accept you for how beautiful you are then they don't deserve to be your friend. Good luck! I hope it all goes well!