"Of course we will do what is best for little one." That's your phrase. Stick to it.
Then do what you, as his new mum, think is right.
What do the social workers know about what is best for little one. They might even be retired by the time he is a teenager!
"I'm just thinking about all the cards we get and all the confusion too." We got very few cards, compared to when we got our birth daughter! Ask for cards once adoption is official, legal, much better then.
"My husband thinks we should just be honest and tell our sw now that I feel really uncomfortable with his name, I'm scared of the consequences tho, I so don't want to jeapodise this."
Your husband could indeed jeaopise this. Maybe tell him you feel OK with the name and then decide when it is all approaching being legalized.
Honestly, you have nothing to gain by discussing this with social workers.
If you are not sure what to call him to friends you could go for a midway nick name type thing... something similar to his birth name but not quite and then people would never know his birth name.
I think being traceable is a very good reason to change a name. Our son's name is unusual. I would say he could be traced. We were told not to change it! I think social workers are wrong to make such a song and dance about the child's birth name. It's not really in child's interests.
Because you have a birth daughter, who the social worker may well see when she visits, I'd be tempted to keep his birth name for first few months, get your dd to call him a nick name which you all like a lot and then change it formally if/when you are ready.