Thanks for your replies, guys! They have been helpful. I think I know what to do now. And that is... wait. Until I have some time to spare for this. Then, after a backup, I will perform the migration. Now let's see that this openrc and baselayout-2 is that I have read people talking about for quite a while here. Emerging more stuff is okay, also small problems here and there. Generally having newer stuff is nice and geekier. I also have some other Gentoo machines I maintain, and there are two people whose machines I look after, so it may help if I see new problems first. The eix-test-obsolete will be much shorter for sure!
Again, thanks for the nice discussion. Wonko