I have pieces here and there among the topics and threads. Some of it is in long lost threads. I'll try to assemble a bunch of stuff soon, hopefully before the transition.
I think I have a Murphy thread somewhere. There is a Ms. Duck thread on Molly=Mab theory which I've used as a template, but mine is more precise and targeted than hers given new information about our Mab's history. This is Ms. Duck's theory. Just twist it like I said with the focus on Murphy instead of Molly for my theory.
http://www.jimbutcheronline.com/bb/index.php/topic,32663.msg1452169.html#msg1452169Now, on time travel in general, I had a future=>past thread years ago, where I argued that some figures and/or knowledge went into the distant past. Essentially I argued that perhaps Skakespeare's work, or some entity like Bob or Bonnie(Lash's offspring) gets left in the past with a history of some of the future literature, which forms the basis of the language for the fae and the archetypes of some creatures, like the scarecrow, etc that had appeared in modern cinema. Bob becomes some sort of basis for Demonreach, Bonnie becomes bound to the first Archive, etc, perhaps Harry's allies assume some mantles of god's when they go into distant past to help Harry fight some bad thing that tries to undo something and is countered by our good guys.
My next piece is based off of both IdHarry and Uriel's hint that "No matter where you go, there you are." I believe this to be a hint that Harry can return to instances of where he had been, just like IdHarry had just visited him. Further, I believe the "there you are" phrase may be a hint as to a time in which Harry may revisit that occasion in the books later on. There are a couple of "there you are" that take place during the showdown at the masquerade in GP, so my theory holds that the masquerade will be repeated with those lines about "there you are" being repeated.
Lastly, I believe that there are ongoing assaults against the timeline to prevent Murphy from becoming Mab. (You could also argue the assaults against the timeline are more targeted against Harry, but I'm a Murphy fan so its all about her.) It has already happened in one timeline, one reality and we are seeing an attempt to prevent it in another. Or, if that doesn't succeed at least so damage her and her pride by taking her "Harry" away from her. Though I'm sure we probably wouldn't see much in the way of her inured pride, but I'd imagine it would be there similar to her injured pride when nemesis got to Maeve.
My Marcone is Harry/Murphy's son and Nic is Malcolm Dresden theory is really just tangential and to some extent beside the point because I'm more devoted to the Murphy/Mab theory and if it falls, the others likely fall as well.
I think that is a brief synopsis of my theories. Did you have more questions specific to time travel itself? Vadderung in Cold Days talks about twinned universes arising out of paradoxes like the one described where you both succeed in killing your grandfather creating a reality in which you were never born and failing to kill your grandfather in which case you likely got your butt kicked with the universe carrying on...