Well, first of all, we know that the Elric Dad was an alchemist, and that he disappeared after awhile, and nothing more beyond that. I dunno, but that alone seems a bit fishy...and besides, who puts random armor around the house? I think the Dad was probably experimenting with human transmutation of some sort, and that things have gone wrong before, and that could be why he has armor around - as a back-up ~ like affixing souls via blood seal onto an armor....??
Then, during episode 23? when Envy was beating up Ed in the laboratory, he screamed that "you're that bastard's son!" This could mean that the Elric Dad was the one that created the homunculus, and that could be why the Sins were looking for Ed in order to turn them into real human using the Red Water.
Tell me what you think.....since right now...I don't think I'm making much sense..'Doh..