Let My Love Open The Door does have a striking similarity to the Final Fantasy prelude, but here's a interesting tidbit. There is another song that Uematsu may have ripped off for not one but TWO of the songs in the FF soundtrack. In the song A Walk in the Black Forest by Horst Jankowski, you can almost hear, note for note, the first part of the Final Fantasy prelude and shortly after, the shop theme.
It's not exactly the most blatant plagiarism, but with strong similarities to TWO songs from the same game, you have to at least wonder.
Was the Metal Gear Solid theme composer Tappi Iwase fired and banned from composing when it was discovered that he plagiarized a Russian song?
No. In fact, not only does he still get credit for the MGS themes in subsequent games (as recently as Snake Eater), he appears on Final Fantasy XIII's soundtrack and is still releasing albums.
Are you sure about that? It was quite a publicised story that his use of a Russian soundtrack song got him in trouble when Kojima found out. While he is credited "as recently as Snake Eater", that was in 2005, 12 years ago. And that was years before MGS4 came out, a game that completely removed the Metal Gear Solid theme tune and lacked any contributions from Tappi, most likely due to the controversy. Since Snake Eater, his only soundtrack appearances on MGS are on compilations.