1. No, you have taken that verse wholly out of context. I suggest you familiarize yourself with the topography of the Middle East. If I say to you go down that road and the road slopes downhill, does it mean that it is necessarily headed in a Southward direction? Of course not! It simply means that you are going on a road that descends. If you were to do more Bible study you would know that Jerusalem is built upon Mt. Zion - a high point in the area. Gaza by contrast is a near sea-level close to the Mediterranean Sea. You have made the simple mistake of conflating direction with elevation. All roads from Jerusalem are down (descent in elevation) from Jerusalem since the city is built on a high point. So for you to claim it is a lie demonstrates you have simply not studied enough.
2. Up and down on a map are meaningless. When you give someone directions from a map do you say go up, or go down or go sideways. Of course not as that would be of no help at all. Only directions matters. Nothing on a flat earth map conflicts with the direction.
3. In order to properly account for the constellations from a flat earth perspective you may not be aware that the Bible refers to the "firmament" in Genesis 1 which describes a vault or dome over the flat earth - picture a snow globe.
Then God made two great lights: the greater light to rule the day, and the lesser light to rule the night. He made the stars also. 17 God set them in the firmament of the heavens to give light on the earth, Gen 1:16-17. Does firmament of the heavens refer to "outer space" as we are taught that the sun, moon and stars exist beyond our atmosphere in the vacuum of outer space. That would be at odds with the creation account as Gen 1:20 states
"Then God said, “Let the waters abound with an abundance of living creatures, and let birds fly above the earth across the face of the firmament of the heavens.” Notice that this verse states that the birds fly across the
face of the firmament. Birds fly in our atmosphere; not in the vacuum of outer space. According to these verses, in the atmosphere in which the birds fly, God also placed the sun, moon and stars. The domed firmament accounts for how we perceive the stars including the South Star Sigma Octantis.