As for pkgbase, it makes sense to package certain applications within certain categories. The entire compiling tool chain can be packaged; each additional firewall aside from IPFW can be packaged; cleartext network applications can be packaged; GPIO, games and Floppy can be packaged. LibreSSL and OpenSSL could be packaged, for those who have the ability to choose. Perhaps what's in contrib can be packaged. Outside of things which don't carry much outside dependencies, it doesn't make sense to package the rest of FreeBSD's base system. It's just work and complexity for little in return.
Packaging within base to a limited extent can help with replacing goals in base. For instance, toolchain components with a completely permissive license can replace GPL components without waiting for each FreeBSD release. Those who want to install LibreSSL and don't need OpenSSL can choose one or both. GPIO is needed for circuit boards or such like projects. Additional firewalls can be chosen from, and perhaps more can be added from other BSD's. Pkgbase can allow a choice of which version of PF to install, to install NetBSD's or DragonflyBSD's firewall. Cleartext networking applications can be chosen to be not installed. Video drivers can be packaged, so those with the newest cards don't have to wait for the next release. Done correctly, the install image can fit on a CD again. Pkgbase would be better standardized than ports and be part of the extended base system.
As for KDE in the installer, I'm not a fan of it. KDE at one time tried to be more permissive than GPL, but it stuck with GPL. It makes sense that KDE has internationalization and accessibility for the impaired, so that could be why it was wanted in an installer. For an installer, KDE seems too heavy. As long as there's always an option for the text-based installer. My desktop is lightweight: I use a combination of mcwm, ittywm and fswm.
As for Rust or Zig, what goes in base needs to be within the C family, and must be able to replace C++ compiling in base, if it means replacing all C++ components. As good as Rust is, since it's not in the C family, it needs to stay in ports. (Zig is in the C family.)