Well it could be, depending no how long you have had it. Generally, ARC does need an occasional connection (even if slow and short) as described in the linked post.
Never tried that but I wouldn’t be surprised. I think it’s mainly for listening.
Indeed, and it’s very annoying. I and others have reported it many times. There were supposedly several attempts to fix it but it still doesn’t work - they have an open ticket to try again.
After a short time? If it’s not because you have been offline “too long” (whatever this is, approx 2 weeks as per the above link) I’d recommend that you open a ticket by clicking here → Support and then Get Help. (They don’t monitor user discussions here in Roon Software Discussion)
Who wouldn’t 
You can leave feedback in Feedback where Roon Labs will see it. (Again, they don’t monitor user discussions here in Roon Software Discussion)