I don't believe that those observations are part of a clever ruse designed by a trickster deity.
I don't, either. It is generally supposed (kind of an assumption everyone seems to make) that Adam and Eve were adults at their creation. The narrative doesn't say, but it is the nearly universal interpretation of the story. When they were only a day old, they appeared to be, say, 18 or 30, or whatever the case may have been. I think the same is probably true for the universe. It was created as a fully-developed, expanding universe, and this may mean it looks billions of years old, to us, even if it is but several thousand years old. Not because He was trying to fool anyone, but maybe that is just the only way to make a suitable universe. I may be wrong about that, and I'd like to look into that a little more in the future. (Yes, to be abundantly clear, I'm down with the 6, 24-hour days, and a universe that is several thousand years old.)
...it doesn't make sense to me that an angel of some special position would be so poorly designed by a perfect creator as to spontaneously become evil in a matter of a few days.
I had never considered the possibility that Satan's tendency to evil was the fault of poor design. Rather the reverse.
I think there's a reason why the angels fell first, and then the humans. Both races fell, not because God messed up, but because He created us to be so like Him (i.e., with the power to think, to judge, to create, to imagine), that we imagined our own judgement was as good as His. The animals (so far as I know) aren't considered morally fallen, perhaps because they don't have the same God-image with which we humans were made. It's beyond them to even consider whether they know better than God, or to ponder some moral code. They simply do what they do.
But we (and I think, the angels) have enough of God's image to make the mistake of thinking we can do without God, or that we can know better than God. It is my (
admittedly unorthodox) point of view that the angels that were going to fall, fell almost immediately, because as spiritual beings they could see God as He is. They knew almost immediately whether they would love or hate Him. We humans, being physical, don't see God so clearly (through a glass darkly, as St. Paul says). It takes us longer to make up our minds. I think that also explains why we don't worry about any more of the angels falling, and why the Bible says nothing about redemption for the fallen angels. Due to their more immediate knowledge of God, their minds are very firmly made up, and always have been. I think that also explains why humans who waver between sinfulness and holiness on Earth, will be strictly one or the other in eternity. When we see God the way the angels see him (without the mediation of the physical world), we will once for all make up our minds firmly to love or despise Him, forever. That is why Heaven can be a place where none sin, and why there is no escape from Hell. (None is desired. Not that people will enjoy Hell, but they know they will never be amenable to loving submission to God.)
But as I said, I'm NOT representing that as any sort of majority viewpoint. That is my own idea, and it's just faintly possible I could be wrong.