Funny, a few weeks ago I decided to do a total re-read, it's been at least 7 or 8 years since I've re-read the books, maybe longer for EoTW - TDR as I often thought of the first 3 books as somewhat outside of the rest of the series.

I've noted a few things so far (finished reading NS and EoTW and about 1/3 of TGH)

1. I think RJ may have had a more clear sense of the OP system than we have given him credit for in these books, but mostly because he was super vague about things until Egwene starts getting POV time during her training. There has been very little so far that outright contradicts rules he sets down later. Primarily things around channeler strength (i.e. Rand is essentially at 100%, or nearly, of his potential when he faces Aginor at the Eye). Most of these details can be brushed aside as anomaly though because RJ was never specific in these books. Rand being the DR and thus a special case can explain most of the things that don't line up directly to later books. But even as early as TGH he started showing us strength increasing for others. Verin gives Egwene a pretty accurate run down of how it works for Aes Sedai which explains why most Aes Sedai take 10 years or more to gain their full strength while other women gain far more rapidly. Egwene grows much more like Aviendha precisely because she isn't terrified of everything she's learning, but she is already showing in TGH a pretty steady progression of strength increase. During EoTW Egwene once lit a fire and Moiraine told her she had enough strength to place minor wardings, consistent with a new channelers (Level 66-58 ). By the first training scene she could JUST make a tent flap move (making her roughly level 57 which RJs notes claim is the minimum to move a feather with air) and is told that she is moving too quickly by Verin in the aforementioned lecture. The Aes Sedai very clearly hold women back while the other women all grow rapidly and seemingly gain close to their full potential within a year or two of beginning. Aviendha, Talaan and Metara show us this pretty obviously.

2. RJ also did some strange stuff with T'A'R early on that he seems to have later phased out (i.e. having real world effects like killing rats) and the whole bit with Tarwin's Gap and I suspect (haven't gotten here yet) in Falme with Rand appearing in the sky during his big OP duels with Ishamael/Ba'alzamon seem to also be quirks RJ later decided to move away from.

3. Moiraine is the biggest factor of misguidance in the first books, especially when you read NS first as she clearly has knowledge in NS that she does not have in EoTW. Why didn't she immediately spot that Rand was Aiel? Gawyn and Loyal immediately do as well as most of the Shienaran soldiers, but an Aes Sedai doesn't. Rand should have stood out like a sore thumb in the TR to an Aes Sedai who has been searching for him for 20 years. It's also odd that she knew to go into the TR on her search since none of the boys would have been in her registry with the possible exception ofRandIF some other woman had passed Kari's name to one of the Accepted in NS. Why/how did she get Mat, Perrin, Rand and a few others birthdays but didn't know where they were born? Only Tam was anywhere near the Battle of the Shining Walls, and no one ever seems to leave the TR to pass along the information, so this is something of a giant plot hole IMO. I suspect this is one of the reasons RJ had originally planned to write more prequels. She also is the source of why we originally thought the Forsaken were VASTLY stronger than modern channelers. She has a couple of different quotes regarding this including saying the Forsaken were 10x stronger than any living sister. Interestingly she also doesn't seem to think all of the Forsaken together had enough power to move 1000 Trollocs from the Blight to the TR. She's both correct and dead wrong in that ... any of the Forsaken alone could easily move thousands of Trollocs if it weren't for the fact that moving through a Gateway would kill them.

4. RJ changed Traveling. In the early books we never really see it except for EoTW Prologue and that appears much closer to teleportation. In fact Traveling in general seems more like teleportation in the few instances we see it early in the series. Descriptions like"Behind him the air rippled, shimmered, solidified into a man ..."or"Desperately he reached out to the True Source, to taintedsaidin, and he Traveled."in and of itself that last one has no real indication of the mechanics of Traveling, but within the context of the Prologue it imparts an instantaneous movement rather than what we see later with Gateways and such. Then we see one last instance"On the island, the air shimmered and coalesced. The black-clad man stood staring at the fiery mountain rising out of the plane"... again imagery that implies more of a teleportation than what we see later.

5. RJ made some changes with Healing too. I don't know if this was straight up change or if he was really exploring how much had been lost with Healing though. Mat's connection to the dagger is and interesting bit to explore as we see on several occasions Moiraine with herangrealand later a circle of 4 Aes Sedai (Siuan, Moiraine, Leane and Verin) with the sameangrealused to perform some form of Healing. What I found interesting about this is that RJ later tells us that at least 1 woman, Alanna, was a better Healer than Verin, and one can assume that the 2 Yellows must also have been. It is unclear what exactly they did in Fal Dara, but functionally it seems as though more than Healing would have been necessary, possibly some form of warding to keep the corruption of Shadar Logoth from spreading. But RJ seems to have actually narrowed the scope of Aes Sedai Healing after this as we never again see non-physical Healing performed by an Aes Sedai (at least until Nynaeve starts working on removing Compulsion and then ends up Healing taint-based madness). In fact, the Aes Sedai are completely stymied by Rand's more meta-physical wounds later in the series. Even Samitsu and Corele can't seem to do for Rand what Moiraine seemed to do for Mat in EoTW and the circle did in TGH. Funny enough Flinn seems to have figured it out, and it's implied that Samitsu and Corele played some role.