Spoiler:
a) harry's temper i thought was a great change. i thought he a little like a gary sue (my friend helped me notice this). so with his temper here, it gave him a deeper side than what we already know about him.
b) well, umbridge is supposed 2 b annoying. that's really the point.
c) i was shocked at first but now, it's worn off. and ppl complain a lot about his death that i start 2 get annoyed with him. i thought that his death was important. it showed us that not every1 is safe and how much it isnt a perfect life 4 him.
d) personally, the 4th book sucked IMO. the 3rd 1 did have a lot of adventures. but i think this book was more aimed 2 explain things rather than have adventures. if it did, then we would probably not know as many things as we did.
e). again, i think that was the goal of the book.