The Treason of Isengard

I have now entered the 7th volume of the History of Middle-earth series. Entitled The Treason of Isengard it will clearly move into what we know as The Two Towers. As usual I will be looking for interesting ideas that never came to be or germs of the finished story that I love so well. With that being said the opening chapter makes it clear we have not reached Towers territory yet. As Tolkien gave much thought to Gandalf's various movements behind the scenes it led to some rewrites of material we've been through multiple times (I've lost count now--perhaps the 6th rewrite of the first chapter?). To start things off Christopher Tolkien assembled various notes, plot outlines, and ideas that guided some of the rewrites which I will highlight in this post:

1. A brief outline of Bilbo's motive: his restlessness for further adventure before death. The hobbit is ignorant of the true power of the Ring. Bilbo "Says to Gandalf he sometimes feels it is like an eye looking at [him]" (p. 5, The Treason of Isengard). No real struggle giving up the Ring. Gandalf occasionally visits Frodo; often years between visits. Frodo decides on his own to leave the Shire with Merry, Faramond, and Sam--Gandalf has been delayed by Treebeard and the Dark Lord's hunt. Aid from Trotter but now Tolkien wondered who Trotter was: "At the end of this sketch my father for a moment contemplated an entirely novel answer to this question: Trotter was a 'disguised elf - friend of Bilbo's in Rivendell.' He was one of the Rivendell scouts, of whom many were sent out, and he 'pretends to be a ranger'. This was struck out, probably as soon as written" (p. 6, The Treason of Isengard).
2. Another note further explores the character of Trotter and we see an important details emerge: "Trotter is...descendent of...the ancient men of the North, one of Elrond's household...real name...Aragorn son of Aramir" (p. 6-7, The Treason of Isengard). Still, Tolkien was not finally decided as in the same scrap notes the idea of Trotter being the hobbit Peregrin Boffin and accompanying details were written. 
3. In his Final Decisions notes (but not quite true!) Tolkien flushed out further details. Of note: It's definitive that neither Bilbo nor Gandalf were aware of the nature of the Ring when Bilbo disappeared. And "Trotter is not a hobbit but a real ranger who had gone to live in Rivendell after much wandering" (p. 8, The Treason of Isengard).
4. More notes detail Gandalf's movements more so than any others: "Black Riders pursue them [read him] - Gandalf has insufficient magic to cope with Black Riders unaided, whose king is a wizard...Eventually he is besieged in the Western Tower. He cannot get away while they guard it with five riders" (p. 9, The Treason of Isengard). Also of significance: the year 1418 is mentioned-the first hint of the Shire Reckoning 
5. More plot notes/outlines: it appears the surname Barnabas has been rejected for Mr. Butterbur. Also Trotter was still captured and tortured in Mordor while hunting Gollum. This survived from hobbit Trotter to man Trotter but was untenable once the identity of Aragorn became more clear. 
6. The final notes are several different sets of time schemes as Tolkien tried to flesh out the chronology of his now massive undertaking. A task that would prove very challenging throughout his writing.