Yes. This is due 30 days rolling window. The downtime will not affect your online score when it will be outside of this window, thus you need an additional 30 days online for each downtime.
However, the online score affects your ingress only when it fall below 60%, then your node will be suspended (no ingress until the online score will recover above 60%).
no, it’s not. Each satellite checks your node independently and in a different time. You may check, when your node was not available with provided scripts.
Your income depends on usage by the customers, the only affected usage will be the ingress traffic (unpaid), if your online score less than 60% and thus no new data ($1.5/TB), however the egress traffic ($20/TB and $10/TB) is still here with the exception of the time when your node was offline. But of course it’s better to fix the problem by figuring out why your node was not available during this time.
The most interesting would be to figure out, why your node was not available for this satellite during this time.
You may search in logs for “ping satellite failed” except “ratelimit” and see - what was the reason.