The third photo definitely looks like pollen.
When you examined the hive, was it a sunny day? Its easier to see eggs on a sunny day.
I ordered/installed three 3# packages this spring. After a week, I examined the hives. Two of the hives had eggs, one did not. I closed them up and came back a week later. I found some eggs but not many in the one hive that I could not see any eggs in the first week. Once the cells were capped in this hive, I realized that I most likely had a laying worker colony because every capped brood was a drone. I ended up combining this hive with one of the other new hives that had capped brood already and now I have a hive that is off to a very good start.
I decided to order two 5# packages, one to replace the one package that turned out to be a laying worker colony.
I would definitely keep an eye on this hive.