Kick the Can mystery

1) In 2017, who kicked the can?
2) In 2017, 4th round of kick-the-can game, why everyone sees Kaburaki in front of them but hears the counting voice?
3) In 2017, 4th round of kick-the-can game, why Kaburaki appears to forget he's the it?
4 )In 2034, why would there be sound of can being kicked?
5) In 2034, who kicked the can?
6) In 2034, somebody kicked the can, why is it still in its original position?
7) In 2034, who did Hokuto hear in Rest Area?

    1)Pipi did it.  According to Tsugumi's personality, she wouldn't kick the can, plus there's no evidence supporting Tsugumi was the culprit.

    2)Assume that Kaburaki did not finish counting and forgot he's it, remember that BW has the memory of 2034 where Hokuto finished count to 100 when he was it.  BW expect to hear the voice count to 100 and that as BW believes, it is reflected to others so they could also hear the counting (works the same way as BW/Hokuto could talk to 2017 Takeshi as Takeshi couldn't see them).  The following is 2017 conversation regarding Kaburaki and the mystery voice.

[Kid]
"What are you all doing here? You planning a strategy?"
[Takeshi]
"No, not exactly..."
[Takeshi]
"Well, I guess we better scatter and hide."
[Kid]
"Yeah."
[You]
"........."
[Sora]
"........."
[Tsugumi]
"........."
[Coco]
"........."
[Takeshi]
"Hey, what's the Kid doing here?"
[Kid]
"Huh? What are you talking about?"
[Takeshi]
"........."
[Takeshi]
"Kid, you're..."
[Takeshi]
"Did you forget that you're 'it'?"
[Kid]
"........."
[??]
"...n-i-n-e-t-y-e-i-g-h-t...
n-i-n-e-t-y-n-i-n-e..."
[Kid]
"Hey...whose voice is that?"
The lights turned on.
[Takeshi]
"W-who turned the lights on?"
[Sora]
"I did..."
We were now able to see the area around us.  You, Sora, Coco, Tsugumi, the Kid, me.... Everyone was accounted for.
[Sora]
"Everyone appears to be present." Sora extended her hand out in the air.
[Sora]
"The life readings of the complex do not appear to be abnormal."
[Sora]
"There is nothing moving around Conference
Room."
[You]
"........."
[Tsugumi]
"........."
[Coco]
"........."
[Takeshi]
"I don't get it."
[Kid]
"Who could have been counting?"
[Takeshi]
"It wasn't you?"
[Kid]
"N-no!"
[Takeshi]
"I thought it sounded like you.... So then
who?"
[Kid]
"I d-dunno."
Kabing!
[You]
"H-hey..."
[Coco]
"That was...the can being kicked."
[Tsugumi]
"Who?"
[Kid]
"........."
[Takeshi]
"........."
[Sora]
"Could it be a ghost?"  Sora said it with a straight face.
[Sora]
"If it is a ghost, I would like to make its acquaintance..."
Splish, splash...The sound of someone moving through the water reached us from outside the room.
And then the empty can came rolling to a stop in front of us.
Clatter, clatter, clatter... The can stopped in a shallow area with a hollow metallic sound.
[Pipi]
"Woooooooof!"
[Coco]
"Hey, Pipi. Where have you been?"

    Sora did not hear the voice, but her reaction was fast as she sees that everyone else seem to be hearing a voice, therefore she turns on the light.  The "ghost" part is just a joke made by Sora who does not hear the voice.  This proves that the voice doesn't exist physically in 2017, it was just projected by BW's misconception.

    3)He had periodic memory lose (In front of the gift shop) before, therefore it is possible to happen again.  The reason for it to happen probably because a) Caused by BW detected the inconsistency between two worlds and tried to correct Kaburaki's memory or b) just a scientific syndrome of his amnesia condition.
Another explanation could be that, Kaburaki did finished counting and was looking for everybody when they met in front of the Lemurian Ruins.  Kaburaki misunderstood the meaning of Takeshi's questions.  But this theory does not explain the counting voice (as people should have heard Kaburaki finishing up counting) and also if this really is what happened, it would be said later in game; but it didni't.

    4, 5, 6)BW projected the sound in 2017 to 2034, where it was unsolved mystery in 2017 of who kicked the cans before the 4th turn, therefore BW expect to hear the sound of can being kicked.  This expectation resulted that the sound was broadcasted in 2034.  With nobody physically kicked the can, it's not surprising to find the can is at the same place.

    7)BW has the memory of how Takeshi caught everyone in 2017, so while thinking he's still in 2017, BW would expect Takeshi to be in the Rest Area therefore hearing the sound (just like hearing Coco's sound in Sara's stuck elevator).  Note this time only Hokuto hears the sound, not Sara nor Sora.
And of course everything happened in 2034 could be planned beforehand... though it is unlikely since BW warned You'haru in 2017 to not to interfere with events to happen in 2034.