Harry being an auror is extremely stupid. He hates following orders (and isn't really that good at doings so) and the aurors are regularly required to do things they don't want to. For example Harry could be ordered to lead a prisoner to a Dementor to have his soul sucked (that is an order that a minster of magic had given which the aurors had to do) or arrest someone even if he knows the person is innocent (for example how Hagrid was arrested for supposedly opening the chamber of secrets). Harry becoming an auror would most likely result in Harry being fired or arrested pretty quickly. I don't like Ron being an auror either but the dislike of him becoming one stems more from I feel he would abuse the power it gives him over others similarly to how he did so as a perfect and how he is shown to do so during the epilogue (Ron used magic against a muggle to pass the driving test for his own personal gain as an Auror knowing it was illegal to do so.)
Hermione entering the ministry is really a major waste of her talents. Fighting for peoples rights (things like get rid of the extremely inhumane prison conditions, improve education, make house elves lives better, etc.) are things she should and would probably do but unless she manages to get pretty high in the government she is not likely to be able to do much working in the ministry other means would probably be more effective.
- I see often enough in fan fics to really annoy me it mentioned that Hermione is a poor liar but prior to the 6th book in the series that really isn't true. She lied successfully to people on multiple occasions such as to teachers (such as Umbridge and McGonagall) and in one of the books (Prisoner of Azkaban) she spent most of the book lying so as to keep her use of the time turner secret. Though Hermione's personality did under go some changes during the sixth book bigger than suddenly losing the ability to lie (were book 6 a fan fic I would have labeled her behavior as out of character since it felt that way to me). Here is a very true quote from a fan fic I recently read:
"Boy, you really don't know Hermione very well at all," he claimed. "She's broken more rules at Hogwarts than pretty much any student at the school! And she's been lying to teachers too, from McGonagall first year all the way to Umbridge just last month!"
- Saw mentioned in a fic Hermione thinking about how Harry taught her how to properly stand while dueling. First thing I thought upon reading that was that dueling is not the same as fighting and it is not something that she really needs to know. Though the major questions that came to me when I saw that mentioned was: Who taught Harry the stances and when did that happen? If it was taught in class then Hermione likely already knows them (unless it was during a class she missed like when she was petrified) and if it was taught outside of class than who taught him? Remus taught Harry the Patronous, Snape somewhat taught Harry how to protect his mind, and Dumbledore watched Riddle's life with Harry but none of them taught Harry anything to do with dueling. Personally I was finding it to be slightly out of character for Harry to teach Hermione anything since other than the Patronous charm (and I'm not even sure about that since Hermione probably read about it and someone mentioned to make the use of the usage of the timetuner a closed loop Hermione would have to have done one - it was an interesting article I saw on a site I visited about the movie Donny Darko) every other instance was Hermione teaching him (such as in preparation for the Tri-wizard tournament, planning the DA meetings - which was her idea not his and I only bring this up because I've seen fics in which Harry created it when Hermione wasn't in the fic and fics that stated it was his idea- and even in his thoughts like at the beginning of the last book, Deathly Hallows, he thinks about how he should get Hermione to teach him some healing spells).
- I understand using the mind control curse and would understand if Harry had used the killing curse but I really don't like or get why Harry used the pain curse particularly on the Carrows (for spitting on his teacher). Using the mind control curse makes sense since it is forcing the character to do what you need or want them to do and the killing curse makes sense since if they are dead they are no longer a threat and can never cause you problems again. The pain curse though is really the most evil of the curses since it really has no practical use and it doesn't make sense to use it since other than enjoying hurting someone a large number of other curses make more sense to use.
- It kind of annoys me when fics make muggles entirely helpless and completely ignorant about the wizarding world and what is going on in it. The main reason this annoys me is because it is likely that more muggles know about and have some type of access to the magical world and magical items than there are witches/wizards total. The reason I say this is because when you consider all the muggle relatives, squibs who have left the wizarding world, werewolves which go to the muggle world to find jobs because of the bigotry of the wizarding world, government officials and past government officials like the prime minister who are informed about the wizarding world, people who find out and aren't oblivated (because they don't say anything and leave the area for example), books and stories from before the muggle and wizarding world split, muggleborns who leave the wizarding world, etc. the number of muggles who know could easily exceed the number of wizards total. Also it is the wizards that are hiding from muggles not the other way around.
- How does anyone know what happened when Harry's parents were killed? Heck how does anyone even know that Harry survived the killing curse since Harry was the only survivor (it is mentioned repeatedly that he was the only survivor) and wasn't able to talk about it. Why doesn't everyone just assume that it was Harry's parents that banished Voldemort and Harry had nothing to do with it. Who told people that Harry went to live with his muggle relatives and his having a scar on his forehead?
- People were coming up and shaking Harry's hand prior to the first book according to the first book and when Harry had barely set foot in the Leaky Cauldron for the first time he was immediately recognized by all the patrons. How did they recognize him? Since Harry was in the muggle world cut off from the Magical world none of them should have known what Harry looked like and yet there is an entire industry with comics and books about the Boy Who Lived.