If I group them all together, I'm assuming they are no longer playing in stereo? (I need to group them if I want to use them with my YouTube music on my TV)

If you group them together they are still playing in stereo, but you will probably experience a slight audio delay from the Play:1s when listening to YouTube music on your TV.

My play ones are beside my TV and I'm unable to move them for surround sound, would I be better just using the beam for Movies without the play 1s?

Because of the delay mentioned above, it would be better to just use the Beam alone for TV audio. But if you can move the Play:1s to the back of the room and connect them as surrounds to the Beam, this would be the much better option so you can have a 5.0 home theater setup.

You might consider getting speaker stands for the Play:1s like this: https://www.amazon.com/Flexson-Floor-Stands-Sonos-One/dp/B0777NGSZG/

If I just want to steam music from my phone, can I have a separate group just to use the play 1s as a stereo pair without the beam and if so how? 

If the Play:1s are grouped to the Beam and not bonded to the Beam as surrounds, you just simply ungroup the Play:1s from the Beam in the Sonos app.

Excellent, thanks for the reply. I see where I was going wrong and getting confused. My group opetion was ghosted out on settings page but I see there is an icon on the "now playing" page that easily let's you group rooms together . 

Thanks again