If you consider Pottermore canon, then yes.

 

Before the epilogue, there was a mention that reports were coming abut the Imperiused returning to themselves and Kingsley becoming acting Minister.

It's less about canon evidence and more about common sense. Dumbledore was the head of a secret order that Sirius belonged to (and supposedly spied upon), and twice in the past he visited Azkaban to interrogate murderers who were framed, it would make sense for him to at least talk to Sirius and ask how much he betrayed them and why, seeing as there was absolutely no previous clue to him being a traitor. I don't want to start another manipulative Dumbledore debate, but it just comes off as weird that he wouldn't at least investigate the matter a bit.

 

It sounds to me like Hermione's comment in book 1 about many great wizards lacking logic comes into play here.

 

We see in PoA that the Order knew there was a traitor, and also that Lupin and Sirius both suspected each other. By contrast, Pettigrew slipped under everybody's radars, and was trusted enough to become the secret-keeper. In light of all that, I don't find it that weird that Dumbledore didn't initially question Sirius's apparent guilt.

 

It's not that Dumbledore should have believed Sirius to be innocent, but rather that Dumbledore should have tried to squeeze all information out of Sirius before leaving him to rot in Azkaban, especially if he believed him to be guilty.

 

Indian wizarding world

Has JKR given any information about it?

 

Yeah. Curry stains, like magic, leaves traces.

 

Some. You can find a relevant wiki article here.

Apparently, India uses flying carpets over broomsticks for transportation, and is the country of origin for Serpensortia. We can infer other things from canon details: for example, the presence of the (presumably Indian) Patil twins, who we can infer are half-bloods or purebloods by their continued presence at Hogwarts during year 7, tells us that there is likely a fair Indian minority in Wizarding Britain. This implies, even if it does not confirm, that India had some amount of contact with Wizarding Britain in the past, maybe even mirroring muggle imperialism in much the same way as Grindelwald's war mirrored WWII.

Of course, that's closer to speculation, but I'm sure you could find at least a couple more interesting details through a careful search of canon information.

 

Question: What was the exact reason Lucius Malfoy put Riddle's Diary in Ginny's school supplies?

Was it to just generally ruin Arthur's reputation, or was it a revenge for a specific incident?

 

I think it may have been both. Arthur was part of a raid team who tried to investigate Lucius for Dark artifacts during the same summer, IIRC.

 

I think it had to do both with the Anti-dark arts raids and the Muggle Protection Act Arthur was pushing for.

 

Oh, yeah! Now I remember. Thanks man. I needed a good reason for him to do it in a project I am constructing.

 

Actually, I once read a really elaborate theory the original plan was to give Harry the Diary, hence why Dobby was so concerned about him. But after Lucius and Arthur had that little fight, he made an impulsive decision to give it to Ginny instead.

It's just a theory, but it made a disturbing amount of sense with all the evidence it laid out.

 

Do we ever get to see the Minister's office, or is it ever described in any instance?

 

The minister is located on "level one" of the ministry building.

By the use of the word "up", we know this is an upper floor.
I don't think the office ever gets portrayed or mentioned, however, although we know it exists because Harry references it in conversation with Arthur in book 5:

Again, the use of "down" further reinforces the idea that the office is on an upper level.

I think that's everything, though.

 

Discussion on the topic of snapping wands has been moved to Why would a wizard get their wand snapped?

 

Do bezoars counteract all poisons? If they did, it would make the 6th year antidote quite superfluous, but that might explain Snape's annotation in the book.

For example, if someone was bitten by a basilisk, would a bezoar be enough? Or is it phoenix tears or death?

 

No canon information that I know of. Given that basilisk venom is one of the few substances that can destroy a Horcrux however, it wouldn't be impossible that phoenix tears are the only antidote.