This is a brand new type, there's no way that equivalent operation to a decades old design with centuries of operational experience can be assumed. Presumably its been designed for high uptime but it would not be unusual for new technology like this to require some refinement.
Yes. The refueling takes the most time but that is planned years in advance. A one-year planned outage every decade can still be 24/7/365 in the other nine years.
And even if a reactor goes offline, a power plant usually operates 2 to 4 reactors, so the entire plant continues operating.