A partial transcript, translated by chronotrig, is found below, though the questions may not be in the correct order due to the source.
By now, you probably understand that love is one of the themes of this tale. In that case, you might say that Zepar and Furfur are the demons who control/represent the truth of the main story. There are many very strong hints and clues in what those two say.
(About Battler's escape)
This part will probably serve as a massive hint regarding the truth about Beatrice.
If you really understand how he was able to escape, it should be possible for you to solve all of the riddles from EP1 to EP4.
Especially after this last game, where we placed several hints that verged on answers, you should be able to explain the riddles of all the closed rooms up until now.
At the end of EP6, they said "we want to have an answer session", so I think that it will include backstory elements that haven't yet appeared in the story, as well as the inner thoughts of various people, making for something that borders on the level of a confession.
Will EP7 end the series?
Who knows? Seven is a lucky number (laughs), and EP8 might become an omake episode, like an "Umineko no Naku Koro ni Rei". (laughs again)
However, I think we will be giving out an extremely merciless answer in EP7.
As for the truth behind Battler's sin and putting Beatrice to sleep, plenty of hints...no, in fact, the answer has already appeared in EP1-6. Quick readers reach the answer in EP4, even more weak points are exposed in EP5, and EP6 gives a nearly definitive answer.
竜騎士 私としては「誰が使ったか」ではなく、「どういう状況下で、何を意味して使ったのか」ということを 探してほしいですね。
Why did Beatrice the elder use the gold truth this time instead of Battler?
I suggest that you consider what situation it was used in and what it meant, rather than who it was that used it.
You should think of the difference in the conditions needed to make 'gold truth' and 'red truth' work.
竜騎士 そうですね。ルールを理解していれば「黄金の真実」は誰にでも仕えるものなので、究極的にはゲーム の「駒」でも使えるものなのです。だからベアトリーチェ（姉）も使えたのでしょう。格闘ゲームの隠し必殺技 みたいにコマンドさえ知っていれば誰でも出せるものです（笑）
In EP5, we were told that Battler's use of the gold truth was proof that he understood the rules, including Beatrice.
Ryuukishi: That's right. The gold text is something that anyone can use if they understand the rules of the game, so ultimately, even 'pieces' in the game can use it. That's probably why Beatrice the elder could use it too. It's like a hidden finishing move in a fighting game that anyone can use if they know the right commands (laughs).
The following portion is from a separate post.
Featherine talked about an answer session. Does this mean that you plan to show in detail the answers behind the tricks and the culprit?
Ryuukishi: About that. For example, in an online game, let's say that there's an ultra-rare item that you have to work really hard to obtain. If that item suddenly becomes easy to get in an update patch, you'd be annoyed and want to get all that wasted time back, wouldn't you? (laughs) In Umineko, if we show in detail how all the tricks work and who the culprit is, people who have reasoned it out and found their own answer will wonder 'What was the point of all my efforts figuring it out?!', so I'd like to create a slight gap between those who have reached the answer and those who haven't.
If this tale were to tell you the answer so plainly that you didn't have to think about it, it would no longer be a game.
For that reason, I want to let people who have thought everything out be confident that the answer they have found is the right one. This may give further hints to those who still haven't figured out everything, but they will not be able to understand the one final point...
That is how I want to write. That is why this work called Umineko is a 'game'.
(Regarding Requiem of the Golden Witch)
Ryuukishi: At any rate, a lot of new information is likely to come out. I think it will be extremely close to the "answer" that the users want. Though I am still unsure as to how far I will actually go.
At this point in time, have any players found the correct method of Battler's escape?
Ryuukishi: I think so. I think there are many people who have found the 'key' that leads to the truth.
However, it looks as though very few people have actually taken that key, returned to the previous episodes, and put it in the keyhole.
In addition, the word "Rokkenjima Explosion accident" appeared for the first time this game.
Ryuukishi: That may have been the first time the word appeared, but the epilogue of EP1 did say that "the jaw was the only part of Maria's corpse that could be found". Furthermore, in EP4, it was shown that Ange's boat was unable to dock at the mansion's harbor and that the remains of the mansion were missing, so it should be possible to link that with "something happened that changed the terrain". So, the words "Rokkenjima Explosion accident" are not a hint, but one of the answers. To go even further, one could say that all things that appeared after EP5 are not hints, but part of the answer.