windows10 xbox live real name/voice chat

Hi, im afraid if i accept a friendship request my real name will be shown, how do i get to the options to avoid this?

next problem i have, is the ingame voice chat (sea of thives) i cant hear or talk to anyone, so far i used ts3, which is annoying.

what do i need to do, to activate/allow it?

thanks for helping me!!

:)