I know Gentoo Linux is not for everyone and doesn't fix the issue of there being wayy too much source to ever personally be able to check it all, however I thin

I know Gentoo Linux is not for everyone and doesn't fix the issue of there being wayy too much source to ever personally be able to check it all, however I think there is something to be said for the fact that the source is indeed readable in-the-clear with most parts of the system and lots of it has even been looked-over by the package/ebuild maintainers. Not trying to say there's no risk, but I think it might reduce it quite a bit if you have the patience! The #gentoo IRC channel is in-my-experience incredibly helpful, totally smashing most types of support from corporate companies out of the water! (Of course that's also only working like that because hardly anyone uses Gentoo.. but I think the point still stands!)