There has been a lot of considered, practical advice to do with political instability, Egypt's economy, education, and also the OP's PND and needing a support network around her. I think all of this is valuable and solid advice.
I absolutely believe that assumptions about the OP's DH and his background (bearing in mind the OP has said nothing about either of them other than what is in the first post) are behind the following sorts of comments (taken from the first half of the thread, gave up after a bit). The assumptions bely a distinct racist thread (racism being, for example, "a belief that all members of each race possess characteristics or abilities specific to that race, especially so as to distinguish it as inferior or superior to another race or races").
"You will have very few rights as a woman in Egypt" - really? Is this a fact, one perhaps confused with fewer or lesser (different?) rights compared to the U.K.?
"It's almost as though he's keeping you barefoot and pregnant to manipulate you..." - where on earth has this come from? I see nothing in the opening post that doesn't require a huge amount of extrapolation to reach this conclusion. You'd only say this if you assume this is what Egyptian men do, habitually (not just occasionally).
"A friend's father didn't manage to take her to his country in the Middle East as a preteen [etc etc...]". Would this Middle Eastern country be Israel, or just a predominantly Muslim ME country?
Multiple flights of fancy of the DH taking his own children to Egypt without the OP and not bringing him back. Where has this come from?! Again you'd only think this if you thought this is what Egyptian men do habitually.
Multiple recommendations that the OP hide the DC's passports - again, what evidence do you have that this might be necessary? Would you say such a thing if the DH were German or a New Zealander in the first post, and not Egyptian?
Assumption that his parents are chipping away at home behind the scenes - once again, you'd only say this if you assumed all Egyptian or Muslim PILs do such things. Stereotyping again.
"If you do, you will never make another decision again. You won't chose the bread you eat" - I mean, seriously?!
"Your children will grow up with values alien to you" - of course they will! And? They are half Egyptian! As much Egyptian as they are British! The OP chose to marry an Egyptian man and have children with them! Are they not being brought up with values as much alien to the DH?
"You will never bring your children back" - again, where to begin with such a sweeping statement...?
"I would start storing the passports at your parents' house" - as above.
"In your place I would get legal advice about getting your children made wards of court, after giving their passports to your parents" - please, what in the OP would indicate that such a drastic step would be necessary or even advisable? I can only assume a racist assumption is behind this train of thought.
"Maybe the in laws have found him a second wife, that's why he is keen to go back" - FFS. Stereotype much?
"Your female children will be subjected to forced genital mutilation against your will, for a start" - pls see above definition of racism.
And so on and so forth. Why the frothiness about an accusation of racism? If the posters of these comments stand behind them, they should own them - why would they not want to be accused of being racist when this is patently what these statements are. Everyone is entitled to their opinions, and nobody can have it both ways: either make such statements and believe in them and their consequences, or if you don't believe in them don't make them.
For those who have asked, no I would not move to Egypt with my children for all the practical, sensible reasons given by many posters. Yes, I live in my DH's home country and my DC are of his nationality; if we divorce I would not be able to take them back home to the U.K. without his permission. I live in the US and my children are American. Finally, I am not Muslim.