I understand how you feel- names feel such a big deal at first. Honestly with time you find it really doesn't matter- they are the same kid whatever they are called.
DD2 had the wrong first name. We were all set to adopt her under a particular name because she'd been abandoned but found out just before placement that the BPs had registered her under a different one.
We kept the name we gave her and bumped the other to middle name.
The problem is it’s the same middle name as one of the BP.
I don’t want to taint it and I don’t want to tell my family member. I feel like I somehow have to prove that ‘I chose it first’ sort of thing. I have already had to accept that my LO’s first name is after a member of the birth family also.
Honestly I think that's perfect. You have a link to your family that will be part of his/her story with added bonus that it's the original birth name, so no complications of getting older and finding out there was a change.
You don't need to prove anything. You will be cleaning up vomit, cuddling away tears, dealing with tantrums, taking them to school, watching hundreds of disney films, not getting enough sleep and asking yourself why they can't learn to flush the fucking toilet.
That's being a parent. Gene donation doesn't compare. It's nice that BPs will have the name connection too- it's so little compared to what you have.
P.S. Your SW is nothing to do with putting the AO application in. You do that after 10 weeks. The only reason to delay is if you want to stay on the books while you wrangle firm written commitments to post adoption support or financial aid (this can be a very effective tactic).
If it isn't that you can put the application in today. Feel free to PM me if you want to ask anything about that you don't feel happy sharing on here.