Veidt's "I did it 35 minutes ago" line and V's "I did it 10 minutes ago" line when he kills Dr. Surridge

The biggest thing is that the timing works. Watchmen ends with an unsteady world peace in 1986. In V For Vendetta, the nuclear strike that allows the takeover of the Norsefire party in 1992 takes place in the late 80’s.
Considering Veidt’s general forethought, minus doing the most idiotic thing possible – trusting man not to destroy themselves, it would make sense that Veidt would go to England, a developed country abstaining from the political climate, which we had heard nothing in Watchmen. During the takeover by the Norsefire party, Veidt would have then theoretically been rounded up as a foreigner and “possible homosexual” and would have been arrested after living a few years safely and comfortably on funds from a secret account.
At Larkhill it is important that Subject 5 or V is the only survivor of the experiments that cause mutations and other effects in the patients. I explain this by stating that Veidt was in peak physical condition and as a lifelong vegetarian it is likely that his diet would make him less reactive in the same ways that the other subjects were i.e. no physical mutations. The results of testing on V are remarked as being mostly an increase of his reflexes and strength (which were already astounding or possibly not even changed by the experiment). The only effect of the testing that was noted was the madness and a destruction of the personality and personal memories while retaining the knowledge. V is shown to have a wide range of knowledge including gardening (note the atrium in Karnal), fighting, philosophy, literature and more which makes sense as Veidt was the smartest man in the world and was incredibly well studied.
Upon his escape, via a long winded plan, V then takes to plotting out an even longer revenge plan which can be likened to Veidt’s plan for world peace. He is able to then find his way to create a sanctum in England, the Shadow Gallery, to steal “objection material” for decoration and then V begins his revenge ultimately fighting for anarchy and revenge. Note as well that in the intermediate time between escape and the revolution, V is able to kill about 40 people without being caught and without a pattern being established (which he did). He is able to prepare for his death and create yet another unstoppable plan that is not fully figured out until it is too late to stop it.
Despite what I see as a commonly easy thread to draw, there are apparently a few Internet arguments about the topic. Common issues include Veidt’s age; the lack of mentioning heroes/ Dr. Manhattan and the over quoted and referenced possible homosexuality of Veidt and V’s relationship with Evey. As noted common issues are the age of Veidt who would be in his 50s or 60s at the time. Consider though that Veidt is noted to have the physique of someone much younger. Additionally the fact that he has been experimented upon would likely make V/Veidt much more youthful. Heroes would not be mentioned because either England had a similar act to the Keene Act or it never became popular. Dr. Manhattan would have been gone for a decade so he would not be mentioned. Finally the Veidt possibly being homosexual is based on the crazy ideas of an insane man and V either way is never truly in love with Evey. While he cares for her, V shows no love of the romantic variety making his sexuality irrelevant.
All of these facts have personally sold me on the idea that V is Veidt. It makes sense and yet it is an opinion that not many other people have. Considering Moore’s capacity for mixing other characters from literature, i.e. The League of Extraordinary Gentlemen, it is incredibly possible that at least these two stories are part of the same continuity.