Cable management

Hi,

I’d like to WLED a whole room. Bottom and Top

PSU is outside of the room. The way to the first stripe 2.5m (from ceiling to the bottom / respectively the other way around)
Please find the graphic attached. (This shows only one part (ceiling for example)

Green = LEDs
yellow = distances
blue = diameter

PSU 5V / 60 AMP

  1. Is the voltage drop really that critical? Do you know if it is still that critical if I reduce to 90% brigthness?

  2. How to solder these thick wires? Or can I use some Wagos and reduce diameter on the last inch?

  3. The blue circles are my power input points. Do I have to sum the LEDs if I input in both directions?

  4. Did I use the calculator correctly in this scenario?

Best regards and thank you!