I think RPG's are fine without complex plots. I also think RPG's are fine
with complex plots, to an extent. There have been almost none that have made me wringe in incomprehensibility . I'm fine with saving the world, I've done it atleast a thousand times already, what's a thousand more? As long as the game presents itself in a entertaining and engaging manner, I think I would be fine with almost no plot. I bet most of you would agree with me if you're a fan of classic megaman, or if you can remember playing some of the third, second, heck even first generation of consoles.
Thankfully though, there are some games that provide us with a plot that is complicated, but is fun to speculate about with other people. It would be a bit ho-hum if there were a world of games with little or no plot, and it would also be a labyrinth-like world if all games needed a 10-page manual to tell the basic story, with 3+ games to figure out the whole story.
Not at all, to be honest, complex plots turn me away from RPG's, thats why I've never played Final Fantasy of any sort. Because I'd rather play Chrono Trigger (Which despite its length is fun enough.) and the DS Geass game, not to forget the Mario RPG's.
I think FF5 and Final Fantasy Mystic Quest would be enjoyable for you then. To be honest, there's not quite as much story in 5 as there is in 4 and 6. It's not really complicated.
Mystic Quest's overworld and battle system is different from the rest.
I think if you can understand Code Geass's story, you'd be fine with these two. Probably with FF3 too. 3's story isn't really complicated either, but it does have its frustrating moments, being that it's a Famicom-era game.