Yes. As explained here: Data archive buckets explained the data is available in 1min, 5min, 30min, 3hr, 1day temporal resolutions. Just click on the " - | +" toggles to zoom in or out to what you want.
Exactly. Once you know the math, it’s obvious. Keep in mind, instrument reporting intervals play a huge role in how many obs are used in the calculated average. Your SKY records an instantaneous observation every 3seconds.