Kids Room ceiling 15m WLED (experimental Phase)

I’m in process of renovating the Kids Room with a partly suspended ceiling.
See the Room here:

The plates are 50mm wider, so i can place the LEDs comfortly besides the tunnel. Goal is to create fancy lightning and design for my son’s new room. For my troubles regarding "how to do it not with 5m but 15m i already found multiple Posts so i kinda already read the most of the issues. (e.g. this)

Still i’'m worried - please share your Opinion on:

  1. One 30A 5v using power injection -vs- 3x 10A 5v Power Supply, directly & exclusively to each 5m?
  2. One D1 Mini NodeMcu -vs- 3x D1 Mini NodeMcu to each 5m?
  3. Relay Board to hard-power off the LEDs or not? Do they really draw much when “soft” switched off?

As i’ve got already everything on the Floor for a dry run (besides the Relay Board) and it functions perfectly using 3x Power Supply and 3x ESP8266 i’m tempted to do so. On the other side im reculant to install everything, just to uninstall it a week later because i messed something up.

For the Kids Room i plan with a total of 900x WS2812B (15m in total with 60 LED per Meter), as i didn’t like the spaces on the 30 LED/m much. I tried 3 Types, as i wanted to try all of em before making a decission on which fits my need.

If nothing goes wrong, i’ll install everything next Weekend.

I tested WS2812B in both 30LED/m as well as 60LED/m and SK6812 RGBW 60LED/m Versions so far.

I never noticed in Videos and Fotos that the “white” on the “normal” Stip is so ugly, till i compared it live to SK6812. For my Bathroom im defenitly going for SK6812, but as there is a additional “normal” White Light in the middle of the Kid room, i’m fine with WS2812B in there.

I’m still in process of soldering cables onto the D1 Mini NodeMcu and putting them into some little plastic cases for protection. They won’t disturb the WiFi-Signal much, will they?

Should not.