When V shows Evey his rose garden for the first time, she asks if there's a rose for Mr. Susan. V replies, 'Oh no, for him I have cultivated a very special rose.' It took me a few read-throughs before I realized he was referring to Rosemary Almond, and another read-through before I realized that this meant that V was probably responsible for everything awful that happened to Rosemary - the death of her husband, the government refusing to give her widow's pension (after all, he can hack into FATE, who says he can't change those records), probably even arranging that the only job she gets is as a dancing girl. V deliberately arranged for Rosemary's life after losing her husband to be as horrible as possible, to expose to her how privileged she had been, and the lie that she had lived - as well as how truly corrupt and vile the Susan administration could be, and to give her the motivation to kill Susan. In other words, V really did cultivate a very special rose for the Leader.
In V for Vendetta, there's a scene where Evey tells V that she doesn't want him to die, and he replies that that was the kindest thing she could have said to him. It took me a few viewings to realize that it was because she knew nothing about V, and that he was the personification of everything for which he worked, that it meant so much to V (he could rest assured that she would continue his work). She had fallen in love with an idea, not a person.
From the sketch: the scene where Sutler unmasks V, only to find that the terrorist is actually himself. Brilliant because in a totalitarian system, the government is the one that's terrorizing the people. Also the fact that they both order the soldiers to open fire, and end up dead - a totalitarian government essentially destroys itself.
Every time you see Sutler on the big screen in Norsefire HQ, his pupils are expanded to the point where his iris is a millimeter band around it. Deranged much?
At the end, when the massive crowd takes off their masks to see the fireworks better, people who have clearly died during the film Dietrich, Valerie and her lover, the glasses-wearing girl, Evey's parents are present unmasking themselves. So, how much of this film is all in Evey's head?
V's calling-card for his assassinations is the Scarlet Carson, a rose specially grown by Valerie's lover for Valerie. Since her story was the only thing that kept V (and later, Evey, although this is unrelated) somewhat sane during V's incarceration and torture at Larkhill, maybe the assassinations themselves are V getting his revenge for her as well as for himself. Oh, and, of course, to bring down the government and to stop anyone identifying him.
Look carefully at the jukebox when V first considers asking Evey to dance with him. He presses a button emblazoned with the number 5. Now, what's 5 in Roman numerals?
Holy crap, what about the symbolism of the letter V?? Evey, Valerie, November the 5th...I'm sure there's more...
Evey's name: E (the 5th letter in the alphabet) and V.
The source material played very heavily on the Fifth of November motif including a copious amounts of 5s and Vs all over the place, some meaningful, some just thrown in because it could be done and because strengthening the motif made the meaningful bits more meaningful. The film downplays this somewhat but still strives for the same effect.
Sutler's last name, while it sounds close to Hitler, also sounds close to the word subtle. Kind of makes sense with all the interpretations behind Adam.
The scene where the Ears are listening to Lilliman's murder. One of them says "Children's Hour at the Abbey." Then they chuckle as they listen until they hear Lilliman calling out for help. Think about how they laugh and listen for a minute and of the comment Children's Hour at the Abbey....you're welcome.
The same old democratic government that had faked a terrorist attack and killed thousands of civilians to get an excuse to become totalitarian. It was to be destroyed and built anew.
The destruction of the Houses of Parliament is retained from the source material (though in the graphic novel it happens near at the beginning and 10 Downing Street receives the underground explosion treatment) where V is much more actively portrayed as an anarchist (per Alan Moore's own politics) and his goal is not the reform of government but rather the destruction of it as a whole.