T2 is not a traditional Linux distribution; it's a source-based meta-distribution. It provides the tools and scripts to build your own custom distro tailored to specific use cases, hardware, or performance goals.
Depends on your machine, but expect several hours on a modern CPU. More if you're targeting multiple architectures or full desktop environments, or build on an older system.
Absolutely, it’s designed to support cross-compiling for all -even exotic- GCC and Clang supported CPU architectures.
In short, T2 is fully automated compared to manually following the LFS book, supports more packages than Buildroot, and more CPU architectures and built-in cross compilation compared to Gentoo.
Yes! Many embedded vendors and researchers use T2 for exactly that purpose. It’s extremely flexible and scriptable.
Some packages need to install files with special ownership and permissions that are not allowed to be set by a normal user. Additionally non-cross build packages are build inside a chroot sandbox environment, which requires root privilege as well. However, you can simply build it in containers or VMs.
Nothing! T2 is released for free under the terms of the GNU General Public License (GPL).
No (of course not). T2 is a build system such as GNU make. It just builds the components together. Whether some components are binary-only with a proprietary license is up to you.
However, of course you have to honor the original licenses from the Linux kernel, Glibc, uClibc and Busybox et al. and publish those sources and your modifications, if any. If in doubt please consult your lawyer for licensing and related questions.