Raspberry Pi for streaming videos on Youtube, Twich, etc.?. Will it pull?

Question

YouTube

I would like to make a separate device for encoding and video streaming on rtpm. But I'm not familiar with the Raspberry Pi yet, and before buying I would like to clarify:
1. Can the raspberry stream at 1080p/60fps? Or at least 720p/60fps.
2. According to what scheme can the raspberry be used: a) the source broadcasts a video stream with a thick bitrate over the network to the raspberry, and the raspberry repackages it and sends it to the recipient. Those. in this scheme, the source is still involved in the formation of the video stream. b) the video output of the source is connected to the raspberry. Here you probably need some kind of adapter with HDMI to USB (it seems that there are such) and the video stream is completely formed on a raspberry.
The first option is easier in my opinion. Indeed, on the same PC it is easy to set up all sorts of overlays and additional sources, cameras, microphones, and so on.
But the second option is also interesting for the future, because. saves the source from unnecessary load.

Answer 1

It turns out maybe https://www.youtube.com/watch?v=S3zNBGfPFxI