A:AnswerYour best bet will be to go here ---> https://gpu.userbenchmark.com/Nvidia-RTX-2060/Rating/4034 this has to be my favorite benchmark testing site. You'll be able to find your information there.
A:AnswerStreaming is not a problem with the PC. The more important question is how fast your cable is and how many users are connected to. Think of it as a road. Some roads are 2 lane while others are 4 lane or 6 lanes. If your internet is a 2 lanes and a lot of cars (users) are online streaming speeds will be slow while a 4 lane road can handle the same volume of traffic easily so streaming is not a problem.
A:AnswerIt comes with a standard generic HP keyboard and mouse. I bought the Omen keyboard separately, and I think it is worth it. (As long as it is on sale of course)
A:AnswerNo, the power supply can not be upgraded. Here is information on the power supply:
Internal PSU 500 W
Total wattage: 500 W
Full range: 115 V/230 V
Efficiency: Bronze