In the Lemmyverse for self-hosting Immich looks very popular (despite their warning : The project is under very active development. Expect bugs and changes. Do not use it as the only way to store your photos and videos!)
You can try to follow the build instructions like mentioned in another comment but be aware that you are trying to build for a platform which has as far as I can see no official support compile instructions for the software. YMMV.
Yes. Haiku is quite light weight, small and snappy. One drawback is that it has not yet multi user implemented (everything still runs as root! But so do old DOS flavors :-) ) but imho it is fun to play with and check which software packages it has (it has several emulators packaged).
You want to try something interesting but want to dual-boot. That last bit could be difficult or "impossible" but using a VM or running from USB stick are options.
https://www.gobolinux.org GoboLinux is an alternative Linux distribution which
redefines the entire filesystem hierarchy. Doesn't seem up to date but quite interesting. If I remember well you can have different versions of software installed at the same time. Let's say (making this up) Bash 1.1, 3.1 and 5.2
https://bedrocklinux.org Bedrock Linux is a meta Linux distribution which allows users to mix-and-match components from other, typically incompatible distributions.
Have other comments made you dislike /e/OS ? microG, which /e/OS uses is not using Google but a replacement for the Google Play framework if you would for example need location feature for some of your apps.
/e/OS is based on LineageOS with microG. They did make a choice for Magic Earth as maps app which is not open source. For "normies" /e/OS seems a fine choice to me to De-Google.
Did you do a sha256sum or md5sum checksum after downloading the iso file and after copying it to the Ventoy pendrive ? (Linux uses caching for copying. Taking the pendrive out before your system has done a "safe remove" can cause problems)