Cost of xfinity stream

I’m got a email saying xfinity stream is included in my service.
Question #1: is there a cost to stream HBO, SHOWTIME, STARZ
Question #2: what all channels are included in xfinity stream?
Question #3: how many devices can stream at the same time?
Question #4: can you stream from Amazon Fire Stick?
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#1. You would need to purchase the subscription through your normal account billing
#2. Whatever is in your video subscription. There are some that aren’t available out of home.
#3. Up to 5 devices simultaneously
#4. Compatible Devices
https://www.xfinity.com/support/articles/xfinity-tv-app-requirements