Where do you see that room assistant connected to the broker? I only see home assistant connecting to the broker.
It’s “safer” to put it in quotes, I do it always like this. However, I noticed an error in your first mac address, all letters need to be lowercase.
The cluster should be created automatically, if you don’t have a complex network you normally don’t need to specify the IPs and ports of the peers.
We can’t tell from the code you posted, because you didn’t format it correctly. See here (especially number 11) for more details on how to format the code properly.
You only need to change the instance name, the rest stays the same.
You need to bind the device tracker to the person. See here for more details.
I shared a detailed guide here on how I set it up in a cluster of 6 Pi Zero’s, which may help you.