Nikola Tesla was an obscure character, to say at least. One of the greatest inventors and one of the most important figures in modern human history, he did us a great deal.
However, it is a fact that he was eccentric to say at least, and his work, although that of genius, has often been presented with a veil of sinister on them. Granted, most of his works were meant for good, but it is no secret that Tesla had plans which, although of noble goals, to say it that way, were very dangerous and with the purpose of destruction.
From death rays to stealth craft, there are numerous conspiracy theories surrounding this men, most of which are work of fiction and delusion created by those who were in awe, and even fear of this man. What's problematic here is that - unlike most conspiracy theories - a portion of those connected with Tesla do actually have some basis and merit, though often minuscule.
However, death ray, for example, was, according to many, an actual idea for an invention which Tesla conjured up during the rise of Nazism, fearing that his homeland, Yugoslavia would be under major assault, as it later indeed happened. There are many interpretations of this so called invention, even though there's little fact to it. However, some of the Tesla's correspondence suggested it was indeed a plan in motion, which, obviously, never came to life.
As far as other conspiracies goes, there are plenty of authors nowadays who have made up their own theories of Tesla's inventions, their purpose and possible plans for future. Majority of these are pure speculation, often unimaginative, and sometimes utterly absurd (I have read some of these interpretations, as early as in my childhood). Still, ideas and inventions such as Tesla Armor in Fallout series is not a that far fetch. I do not believe there is much merit behind that, or even some quality assumptions that Tesla had such inventions on his mind, but, judging by his work, his own imagination and everything in popular culture associated with him, that Armor does indeed deserve its name and is perhaps one of the rare few inventions of science fiction connected with Tesla that could one day be created. However, that is just some speculative fiction connected with Tesla which rises a bit above the other works of this sort.
On the other hand, if we look to the more "human" side of Tesla, his eccentrics, work and ideas, we do indeed see a man who was, and will probably always remain ahead of time, surpassing many which will come after him. He was a prodigy child, and there are plenty anecdotes about his wild childhood, school years etc. (I can name a few a top of my head right now, since I learned those in my elementary school - it was obligatory). Most of this anecdotes are, granted, just that, but there is certainly some dose of truth to them.
That being said, I could probably supply you with some anecdotes from Tesla's life, if you're interested, and a few bits and pieces about all conspiracies related to him, but I can't promise much. We're at the point in time, where, due to the lack of real, solid evidence, it is hard to tell where is the line between "Tesla reality" and "Tesla fiction", which is hardly surprising.
It is common knowledge that after his death FBI impounded all his work, much of which was still in progress, and kept it top secret. Some of his possessions were later given and are placed in Nikola Tesla Museum in Belgrade, but it is not unreasonable to doubt about how much more of his works, patents and documents are still held top secret by US.
As for his involvement and appearance in alternate history of Fallout, it is an interesting idea. However, I'd have to disagree with some things you mentioned, and if I may, make a few suggestions.
First of all, I do not like the idea of Tesla appearing in-game, be that in person or as some AI. House was an interesting character, original one, definitely, but adding Tesla on a relatively similar pattern would be a bit redundant.
That said, I'd have to point out that House was not a real person, although based on Howard Hughes (I also think there is a dose of similarity with Tesla there). My point is that adding Tesla would be perhaps a bit over the top. It may be a diverged universe, but I'm not sure how could one exactly portray Tesla so that he is a faithful one, and not offending of the actual person (don't get me wrong, I'm not saying you aren't able to do that, it is just that the risk of failure is high, considering that there have been many attempts of this sort in the past, especially in video games, and only few of those are actually good). I should mention however, that it is somewhat my personal belief not to make any sort of fan fiction around deceased people, which involves them directly (e.g. I have nothing against fictional Tesla device, but adding him to the story I find abrasive).
Now, to suggest, if I can.
I find the idea of a Fallout game revolving around Tesla and his works to be a brilliant one. Like I've said before, adding Tesla in person would be a bit too much, but a game, or at least a DLC/mod where one explores the past behind some of his (imaginary) works, remains of his laboratories etc. discovering his lost patents and essentially revealing the past and Tesla's influence on the pre-War world, USA plans on making superweapons based on his documents which would destroy China, their failure to do so etc, his connection to the "shadow government", Enclave, how his works could influence the life and balance of powers in post-War world and so on.
I'd leave the specifics to you, since the core idea is yours, though I could probably devise some background myself if I were motivated enough. You get the general idea.
In any case, I wish you luck on this one. I'm definitely intrigued by the idea, since I've always felt that Tesla was badly explored and exploited man in most works of fiction, but adding one of the greatest man to my favorite series which is also "suitable" for such an mixture, is something I would look forward to.
