I repeat: you can't fake a Skype call!
You can absolutely pay someone to pretend to be you on a Skype call.
Although honestly, I'm not even sure what a Skype call would achieve at the moment. As I said before, you have admitted your online accounts and wallets are frequently used by a known scammer (be that you, your brother, your boyfriend, whoever). Proving that you are a 19 year old girl changes none of that.
That's a good point. Ideally my brother would come on to clarify it, I'll leave that to him. As far as I can see, there have been accusations leveled against him but he has not scammed anyone that I can see.