1. Yes

2. No

When Grouped all in the Group will play the same audio.

You could Group more than one Play 1 with the Beam.

It would be a good practice to start each group by adding to the Beam rather than adding it to a Play 1.

Thanks Stanley I'll go looking for a Sonos Beam to do that then! 

The lag you’re experiencing is most likely some form of wifi interference. This would slow the ability of the controller to send commands to your speakers for them to execute. 

Ah! Would a Sonos boost help solve this issue? The old owners left that behind as from what I understand, it’s an outdated product. 
 

wifi connection is excellent and good in all play 1s 

Not likely, although there is some slight possibility. I’d read that FAQ first, and apply what changes make some sense.

I would suggest the BRIDGE is out of date, the BOOST not quite yet, although the latest speakers from Sonos don’t connect to it. 

I understand that playing music works, but you said “a considerable lag between controls and the Sonos Play 1s. ‘, which suggests issues with the commands being sent to those devices. Normally speaking, you shouldn’t have any perceived delay when sending commands. At the least, try changing the WiFi channel your router is using, in case there is some random interference blocking your controller communicating with the speakers, and vice versa. But there is a lot of other things in that FAQ.

The control delay can be frustrating, Sonos support found mine after I failed. I had two speakers, in different rooms, but backed up to the same wall. Moving them a couple feet apart really made a difference.

A diagnostic and call to Sonos support can sometime be the best option.