I noticed that you are focusing all of your attention and energy on informational time travel techniques. This works fine, but there is a lot more to it than computations.
One point you made certainly caught my attention, and that is the point of verification. This aspect will probably never be resolved, because a given target, regardless of range, can never be verified. This process can be demonstrated mathematically, but I am not the one to explain it. As a result of the 'verification problem', most of our projects focus entirely upon attempts to gather not only information, but also physical artifacts, in an attempt to acquire some type of evidence that we have indeed time travelled. The process is exceptionally difficult. While we can retrieve valid physical artifacts, and recorded information, there still remains no way to prove that such is nothing more than some sort of alteration of the present, or, as some think of it, a type of parallel existence. Due to quantum law, it will never be possible to know for certain if we are experiencing actual past events, or simply a parallel version of our own 'present'. Also, if you continue to make any type of s here, you will be included in their hall of shame. At that point I would suggest creating some type of fictional expressions; if you tell them the truth, they will not believe it. If you lie, they may believe it. And then, perhaps we can continue to attempt communications at this address. Otherwise, we can not do so. And once again the dilemna arises; is anything we observe here really from 2013, or, are we deluded consciously, as a result of our lab's mechanisms of altering our own present locale and our conscious awareness of such? This question unfortunately has no absolute answer. I could get into the more complex reasoning of why this technology is even being pursued, but this is not the place to do so.