[Rias]

Recently just re-read (actually re-read a couple weeks ago but didn't have time to gather my thoughts), and definitely came out with more theories than before. These are just my theories, could've been influenced by others who have posted on this thread. Maybe it's close to the truth, or maybe just worth a laugh:

Spoiler for Meta Beatrice vs Meta Battler:

Definitely seems like it's actually Ryukishi07 vs Readers. Meta Beatrice is out there to crack down on the deuctions that players have made in Ep1, such as hiding under the bed during the closed room, dead people are actually just fake corpses, secret passages, duplicate keys and what not. Many things that Battler had came up with I was able to deduce before he mentions it, and thus could even foresee the trap that she laid for the 2nd closed room: that itself was more scary than the murders. Of course, Battler's refusal to suspect anyone in the 18 people group is his downfall; things can be explained easier if someone from the 18 is actually the culprit. In other words, I would actually be quite suprised if none of the 18 is actually crucial in the whole murder case.

Spoiler for So, what's with all those butterflies, goat people, magical blades and what nots?:

First time I was reading I was merely enjoying the story, and definitely got pull by Beatrice's pace. Although I refused to acknowledge that magic was in play, that was merely just my human ego at work, that I refused to give in but did not have a good reason to counter Beatrice's points. Thinking again, after the 2nd time reading, it became more clear to me: It's just the same as Onikakushi-hen from Higurashi. However, there doesn't need to have some disease that makes people delusional; in ep2, the perspective of the story changes from time to time. Sometimes we see it from Battler's or other people's view, sometimes it's 3rd person omnipresent. Everytime magic is in play, it's 3rd person. Thus what we see is actually "actual crime" + "Beatrice's spin on words and claiming everything is magic".
This is also aparaent when we consider that the time line jumps from time to time. Meta Beatrice vs Battler could have happened after Battler gave up, and Beatrice claiming everything was done by magic at the end. Beatrice doesn't necessary have to help the real killer, but has definitely done her share of spreading paranoia and confusion to the players.

Spoiler for What's with Beatrice walking into the house?:

This is hard to fully duduce as it could have 2 beatrice, the real witch and the one that pretends to be her. There are many candiates, but I think the most suspicous is Rosa. If the "fixing candy" event was fake, as she's the only one who saw "Beatrice" fixing the candy, then the "7 brothers and sisters acknowleding Beatrice" is also fake. That would definitely put Rosa as one of the wolves, but I cannot see why it is necessary for her to pretend to be Beatrice. Beatrice never showed up in ep1 and people were still killed off as is...

Spoiler for From the last point, does that mean XXXXXXXX is the real culprit?:

Rosa is definite suspicous, but I doubt she is the only wolf. During the 3rd closed room, there must be someone else who caused the chaoes. There could be more than 1 servants who is actually a wolf...two ways I see this could happen:
1. Kurata/Genji/Shannon are all wolves. Self explantory.
2. One of the three is a wolf. But that would actually mean that someone isn't actually dead and were one of the wolf. Somone used Kannon's dead body to gain entry to the servent's room, and after killing Kumasawa and Nanjo, and when the three runs away, one of them would leave their key behind for the culprit to clean up and move the bodies (perhaps an accompliace from the start, or perhaps was convinced by the culprit on the spot), then afterwards the "one" will get his/her keys back to show that they are innocent.

If point two is indeed the case, then Shanon and Genji is the most suspicious. Perhaps they were with Ginzo during the 1st room, but Ginzo never said how long they were there for. For all we know, they could've finished early, went to Jessica's room and does their business and go back to the dining hall just to pretend that they just got back from Ginzo's room.

Spoiler for Then what about the 4th closed room?:

Recall 34-tan's hint in the hidden tea room. Beatrice has great moves, but sometimes she makes unnessary moves just becuase she's winning or wanted to drag out the game. For the 4th room, people are so tired of these closed room that they failed to carefully check the room like they did for the 2nd and 3rd room. Thus one can argue that it's the old trick of "hiding under the bed". Beatrice only said there's no hidden passages and no hidden places to hide (red text), but recalled the definition that Beatrice had for those terms. Furthurmore, she also did not use Red text to deny the fact that there isn't other people in the room at the time, unlike how she did it for the 2nd and 3rd room.

Spoiler for So in Summary...?:

Beatrice exists but doesn't do anything that helps or hinder the wolves. Rather, she's taking credit of the wolves' work. Also, the crimes are not done by magic.

Spoiler for various unsolved mysteries and speculations:

1. What happened to the inital letter that Rosa got from Beatrice?
Perhaps she read it in the chapel. Or she just plain forgot about it. Who cares about some suspicous letter anyway?

2. In Umineko, who's Berkenstal playing as?
I am guessing Maria...or maybe Saba. Just look at all the help Saba gave, espeically them Saba jokes. Definitely makes Beatrice jealous in hidden tea party

3. What's the deal with the banquet at the end?
It's as it is, party time for everyone. Once battler gives up, there's no point staying real, is there?

4. Then what about Rosa Musou right at the end?
Probably same deal. Or perhaps someone called speical forces "Sea Cats" to retrive the lost gold that Rosa has.

5. Who's Ruon anyway?
Kanon, Shannon, Ruon are servant... maybe more "on"s will show up in Ep3, like Mion and Shion.

Later when I have more time: Deductions from comparing ep1 and ep2.