the ebuild should normally be GPL-2 like other ones. we sometimes use BSD-3 as we've been a bit lazy. it's fine for the ebuild license to be diff from the package's own license.
as for what license your project uses, we can't tell you. the author/owner of the code (sounds like Logitech in this case) are the only ones that can decide the license for source code they produce as the copyright holders. similarly, whether your project complies with licensing requirements of dependencies is for your lawyers to determine. we (CrOS/Google) cannot provide legal advice on these matters.
if you're asking "what should i do to make my life easy", that's easy. MIT or BSD-2 or BSD-3 is the easiest thing to process. and release it on GitHub as OSS. that simplifies the process greatly.
-mike