@InFerNo if it's not a boot drive, you can use gparted to copy the partition over - it's copy and paste, literally. Then set flags using gparted as well. If it's a boot drive you'll need an additional step after to use boot-repair to fix the boot sector and load grub onto it.
It's really simpler than it sounds, I've used it a few times myself. You can also use an #Ubuntu iso to execute this process after booting from it to ensure the 16GB partition is not in use when trying to copy it.
@amazingsparrow
Sounds like you have a specific set of needs. Changing OSes can be like moving homes or learning to fly a new airplane type. It'll takes time & trial/error to get everything dialed in just right.
Most people I've seen have success with debian-based LTS variants. Debian/Ubuntu /Mint. Long-Term-Support = 5 years or more of consistency. There's broad h/w support for both Debian and rpm-based linuxes, so either flavor would work, but unsure if rpm-based have LTS options.