It could be Remus Lupin who dies - he is the last marauder after all - but JK's already confirmed that Wormtail won't be the one to kill him
In answer to the short one first. Wormtail isn't powerful enough to kill him. Voldy will I reckon.
To this thing just go with my answers to the corresponding one in number order.
Hogwarts will reopen: (Solid Evidence) As JK said that someone in Harry's class will become a teacher.
Harry will return to Hogwarts due to strong persuasion from an unknown character, but will nonetheless go to Godrics Hollow on one of his little expeditions. (Probable)
Dumbledore is dead as in dead dead dead. But due to the benefits of being headmaster he will be able to provide advise for Harry.
With Dumbledore dead Voldemort will move in the open and both Wizarding and Muggle world will feel his wrath.
Voldemort will destroy the Ministry of Magic (Probable)
Ginny & Neville's magical talents will shine like we've never seen it. There powers will be influenced as Fred/George and Neville's Grand Mother will die.
Aurthur/Molly will die or Mr./Mrs. Granger.
Hagrid Will be taken down by Voldemort himself. (Guesswork)
Grawp's fury will be shown. (Guesswork)
Hufflepuff's Cup, Slytherin's Locket will be destroyed. (Solid Theory)
Gryffindor's Sword was somehow made into a horcrux at some previous time. (Guesswork)
Something pertaining to knowledge will be the horcrux of Ravenclaw.
Harry, Ron & Hermione will attempt being animagus, will succeed. This will be there first weapon on infiltrating Voldemort. (Guesswork)
R.A.B is not Regulus Black. (According to JK)
Snape has a good streak in his dark nature thats why dumbledore has trusted him to the end. (Probable)
Snape is working for himself being one of the most accomplished legilimens he is able to fool the two greatest wizards in the world.
Peter Pettigrew will die saving harry in order to pay his wizarding debt to harry for saving him. (probable)
Ron & Malfoy will have a nice little confrontation
The trio will master the magic behind the Avada Kedavra
Hermione will kill Bellatrix in a face - off
Sirius is dead and had to die for a reason. (According to JK)
Hogwarts grounds/ Godrics Hollow will be the place of confrontation between Harry & Voldemort.
Voldemort has a weakness. The Blood that runs through his veins belongs to harry and will be part of Voldemort's Downfall. In (GOF) when harry told Dumbledore of how Voldemort's resurrection happened, there was a gleam of triumph in dumbledore's eyes for a fleeting second.
Harry will return to the department of mysteries before Voldemort destroys the Ministry of Magic to find out more about the veil and will end up finding more about the locked room in the Department of mysteries.
Harry will use the power contained within the Department of Mysteries to finish Voldemort. As Dumbledore told him that the power contained within the room is more powerful than nature and human Intelligence and as Voldemort has stretched the boundaries of magic so far, only that power is great enough to destroy him. (One of my strongest theories)
Ron will die to save Hermione. (Most likely)
Harry will be stripped of magic after he had to use all of his to defeat Voldemort.
Voldemort will be vanquish in the end.
The Wizarding World will be rid of evil until Draco junior is born. (LOL). (Most Unlikely)
After his magic has drained he refuses to return to the Dursleys, But takes up residence with the Ginny
Hermione ends up being with Neville.
Since the final word in the book is scar...........i think the last sentence is. And only the creator & the bearer will know the true reason behind the great Scar. (Total Guesswork)
Yes, yes, yes, yes, maybe, yes, no, yes, yes, yes, no, yes, no, yes, yes, I think so, maybe, no, no, most likely, no it'll be Lupin, yes, Godric's Hollow or the graveyard maybe? yes, maybe, thats possible, yes, I don't think so, yeah sure, why not it would be funny and Harry junior can fight Draco junior, second part yes first part no, no and finally a no from me being Vo...actually it might be possible but I doubt it. Or something of that nature anyway.