I sure didn't (well, I actually think it's not supposed to be a clear ending and that you're more or less supposed to come to your own conclusions). Which is amusing because I have no problem at all understanding this run of Action Comics. Like, I don't even have to think about it, and it's actually pretty straight foward. Maybe the episodic monthly thing doesn't help, but if I have to be honest with you, it seems to be more about you not remembering some things than things being especially uncomprehensible. Like the problem you seems to have with the "Comet and the Wanderers" line. We aren't told who the "Wanderers" are, but we do know that Comet has been chosen among others "special people" from other planets by an alien race to fight the Multitude (it's stated by Adam Blake in the back up of issue 0, and Comet pretty much says so to Suzie in issue 11 and 12). From this, it seems pretty logical that these "Wanderers" are the people chosen by these aliens. From this, the "Comet and the Wanderers" line is just Superman calling everyone he can for help to fight the supervillains. Now I can understand why you would forget about this on a daily basis with other stuff to do (I happen to have a good memory).
I could have used David Lynchs movies as an example too. Some of them......I have really have no idea what really happened.