You've got to be kidding me. You like it! It's so unconventional, I've only met a few other people who actually enjoy it. That said, I'm very happy you can appreciate it. I love that it's a much different game---and I'm glad you see that as well. It is addicting, no? Now, on with the questions:::

1. Yes, I have gotten the the last ending. Getting the weapons really isn't that hard. There are only a few that might be a bit troublesome, but no big deal, really. Besides---I kind of enjoyed getting all the weapons. Although I recommend not doing it like me, going to get them all at once. It's not as bad as you might think--there are a couple of really good ones out there. Kings Blood, for example.
2. Personally, I really liked the fifth ending. But that might be because I'm a bit disturbed---without spoiling, all the endings, as you may have foreseen are very, for lack of a better word, unhappy. Melancholy. They're sort of depressing, but very well-done. I hate it when people automatically think sad=bad, or badly done. Since you seem to like Arioch, though I don't think that'll be a problem. They're very good. I've said that my favorite is the second ending, but now I'm not so sure. They're all excellent in their own ways.

But---I thought the fifth ending was worth it. If not because it as good (which I'll get to later) but because if gave me an amazing sense of accomplishment. Finally beating it felt great. Although I could see why some people don't like it, I thought it was very fitting; in my opinion it was happy. It could be considered the happiest of all. The last battle was also very well done---original.

3.Ah. I see you have good taste. At first I didn't like it, because I heard the japanese version first. But it's grown on me; the lyrics are beautiful. I believe the name of the song is Growing Wings, although on the soundtrack it's listed as "Route B Staff Roll-Exhausted".

Anyways, I'm really glad that you like this game. Oh--and you haven't even seen disturbing yet, trust me.

Ah, I love this game.