No, they were chosen because of the dates of other existing celebrations which had astrological significance. The astrology was significant for the old celebrations, not the new. In the case of Christmas, most likely the date was chosen because of the existing celebration of Saturnalia.

Bethlehem is a real city that was around at least 1300 years before Jesus was born. There are several possible meanings of Bethlehem including House of Food, House of Bread, House of War... However, it's also believed that it was named after an ancient fertility God and there have also been claims that this is the origin of Jesus too. If this is true then the etymology is likely different.

If the Bible is so much about astrology why do they seemingly try to obfuscate it entirely behind metaphorical content? Why are there a number of verses in the Bible that denounce it? One of the most direct probably being:

Isaiah 47:13 – “All the counsel you have received has only worn you out! Let your astrologers come forward, those stargazers who make predictions month by month, let them save you from what is coming upon you. Surely they are like stubble; the fire will burn them up. They cannot even save themselves from the power of the flame. Here are no coals to warm anyone; here is no fire to sit by.”

But there are others. See info about the Chaldeans, the origin of astrology and divination and the prohibitions against divination in the Bible for more. Even the apocrypha have denunciations of astrology.

The Bible basically says don't do astrology in a number of ways and places so Christians don't do astrology. I would think that would be obvious. Hidden messages are like conspiracies. You can find them in anything if you look hard enough. Sometimes you do have to read between the lines but you have to read the lines first.