It's definitely a battery killer. You can try it and see for your self
oh, I tried and I saw.
just couldn't believe my eyes! The battery percentage went down like a countdown timer. Ended up mounting the Note 5 on a tripod and connecting it to the charger.
Don't know if it was my Verizon 4G connection, but the YouTube live broadcast always had a 7 or 8-second delay. For example, if I turn my head, the person watching it on YouTube Live wouldn't see it until 8 seconds later.
It also uses a lot of bandwidth. Almost 27GB when I was done. Good think I stil have Verizon unlimited. Didn't use my house wifi because it was only 4mbps up. On my Verizon 4G, I get almost 22mbps upload speed.(51mbps download)