i think it's a classic time rewind ability, and i think she has repeated these events quite often already to know this level of detail

the main questions about her is how did she find out about all this(since they were away and i wouldn't think anyone related to mc is going to tell about it) why is she willing to go this far for him(most people often forget these kind of childhood relations, she probably had an entire life unrelated to him she is discarding) and obviously how she can time travel. for mc i really want to know what he did to trigger this, it seems something happened, but is it his fault and something that would actually merit this much hate. the only thing i could possibly think of is him causing a death of someone that could possibly lead to both him being bullied and his family falling apart but if it was that fmc would know about it and would either not help if it was done in malice or could prevent it if done on accident/not his fault( but in that case she might be doing it the way she is to get revenge even though taking care of the root of the problem would be better for mc's mental)

no... the god of the jews is the same god the Christians believe in just named god

and sorry to be that one guy but Hebew/"biblically accurate" are not in fact accurate. actual normal angels just look like men, not like babies or Cthulhu monsters

no they aren't and they don't even have a concept of satan in their religion it's a christian thing

yeah, but they still use it, hence cooking ingredient by technicality

some people add gold leafs to their food. you make it out of gold hence gold could be considered an ingredient. also someone here clearly never ate Rorona's Gold Pie https://i.postimg.cc/Fs5N7Ybf/i.jpg

not as bad as some other ending recently. but this feels like it could have used some 5-6 more chapters to round things out properly

well i guess that debunks some unfounded theories someone has a while ago

i disagree since i think most plot threads apart from main couple ended meh. and it's more about the resolution of the main problem, which was the arc before the ending arcs

kaguya ending was meh but it was more ass on other characters resolution and and how they resolved the main problem. this is just ass. i hear aka is making another manga, not gonna read that

he is probably fine, remember Ichikawa's early days being all edgy like that too(but not actually having a box cutter, just random intrusive thoughts) it's probably someone else in the class

courage? this is already some of the dumbest ways for this to end with the so called smart guy plan being so incredibly stupid and then he actually dies. this is actually fitting with his aka's endings so far Kaguya's happy end had to rely on the opposing party being incredibly incompetent and stupid for them to lose easily. this tragic end had to have the usually calculating Aqua do the stupidest thing possible for him to die like this

while Roars seem kind of good the rest are still very horrible to humans. which is exactly why they are basically forced to be the starters of this war to most likely get wiped out so the other bloodlines have an easier time

did you actually see what happened in the first few pages of this chapter? gender is very relevant. moreover the MC refers to him as brat and would probably be able to tell if female. also he existed way before MC's daughter was killed.
as for your points:1. can't think of a reason atm but the other points are weaker. 2. woman who lost her only child and joined a cult happy to feed what people assume is a kid, it's not a surprising outcome since she was and still is mentally unstable to do these things. 3. he is a cult leader most of them have their cult treat them like an object of worship or a king and are usually perverts. 4.basically impossible since gender doesn't match and IT IS important.
i think it's possibly more logical the cult leader is a replaceable youth and another one controls the cult then your theory. though a weirdo is still an option

nah this is very obviously referring to Super Mario 64 speedruns , those have been kind of popular again recently

he had a daughter...

??? how would that make sense i don't recall any mention of other kids he had with his wife.

and so will this series soon since it's ending

i don't think there are actually any spoilers to begin with, i think this series started last month so this is probably the most recent chapter