Steins;Gate novel/anime differences list and random theories

That's not to say they are doing a bad job.
It's just that the novel has so much stuff crammed into little corners that they probably couldn't keep it all.
The figure I kept hearing was "50 hours of text," so try to put that into 24 episodes of 30 minutes each and well yeah.
Anyway this will be updated semi-regularly.

1. I am 99% certain that the girl on the rooftop preshift (before the first worldshift) waving off spectators from the roof explosion (where you see an intact device), is Baito Senshi. In the anime it shows someone with a hat over their head making an "X" gesture with their arms, in the VN however you hear her voice, although the scene is not drawn. It sounds like her a lot, the anime seemed to exchange "sounds like her" for "looks like her."

2. When Chris first asks Okabe preshift in the anime about what he wanted to talk to her about 15 minutes back, she says the phrase "it sounded really important." Literally, the phrase was more along the lines of "your face looked really anxious." However in the VN, Chris says something more along the lines of "you looked like the world was about to end, and were about to cry." To me this is a pretty huge distinction in depiction of an emotional state. It conveys a sense of desperation.

3. The first banana experiment actually ended up with the bananas being frozen. This is because Mayuri had put them in the freezer, and then they had removed them to thaw and then warm them up. Of course, this royally fucked up all their future analyses, because they couldn't recreate frozen bananas. Instead they got gel bananas, so they were wildly grasping at straws such as "change in density" (Okabe even says isn't that what a normal microwave does anyway!?)

4. Okabe actually visits the shrine (the first time we are introduced to Ruka) because he semi-believes he is possessed. This is because not only is Chris not dead, but she is vigorous enough to crush him in an intellectual debate. Of course he's half joking here and the whole evil arm thing is just having fun with Ruka.

Theory Fighting:
I'm doing all in my power to avoid spoiling myself ahead of time, but these opinions will contain spoilers as I progress further in the anime/VN of course.

1. Baito Senshi is on the rooftop with the device? satellite? as this story begins.
2. Chris's life or death effect on any timeline is huge. This is evidenced by when the first shift happens, John Titor disappears more or less from the year 2000, and a satellite crashes into the conference hall. To get more of an idea of her importance however, consider an example of where you went back in time and saved the inventor of the time machine. This means her butterfly effect is huge, if it was small, there would be no way a further event in the past would be completely changed, but it was.
3. Okabe's first message about Chris's death saved Chris from dying. However, it might not have saved her directly, but through butterfly effect. I believe this because something is not right about the supposed first time Okabe talked to Chris. The chronology goes something like Okabe tries to desperately talk to Chris, gets interrupted somehow, then 15 minutes later Okabe meets Chris again but has no memory of their previous discussion, then Chris dies, then first world shift from the text. Given the rules of how their text time machine works, what should have happened if it had saved her directly was 1. Okabe never talks to Chris or never enough to catch her attention 2. Chris dies 3. Okabe D-Mails 4. Timeline changes to one where Okabe gets a text from the future, has talked to Chris, and has prevented it. 5. World resynchs and Okabe doesn't remember 4.

One of the frustrating (or intriguing, and I find it clever) features of Okabe's time travel memories is that every time the world shifts they are more or less false. This means that he has to figure out what HE HIMSELF has been doing in the new timeline from the point of change up until he resynchs with the new timeline.
This is why the first occurrence of non memory is odd. Normally when Okabe has no knowledge of what he has been doing, it is because a new timeline has been created, and Okabe "synches in" after a period of time has passed with no knowledge of anything from the point of change up until his synch moment. In this first situation however...there is no synch in. Flat out, Okabe is listed as having done something he has no memory of, but there is no synching in, he is perfectly aware of what he has been doing (walking around with Mayuri) up to that point, there has been no shift, he is not stuck in limbo, he is in control of his faculties.

To me this points to the "15 minutes ago" Okabe as actually being a physically different Okabe, rather than an Okabe who has been given a text from the future. Which implies at some point that the lab gets access to a physical time machine.
4. Baito Senshi is from a future where Chris fucks up (not hard to make this hypothesis.)
5. Moeka did not send the message she said she would (to not buy a new phone 4 days in the past) This is a strong guess because neither Okarin nor any of the lab members actually look at her text before she sends it, and also the results of the message have a surprisingly high change factor.
6. Probably obvious, but Okabe is actually really self-aware of his idiosyncrasies, but enjoys them anyway. I can't really call him delusional or insane.

That's it for now.