MAn and woman are both the same in term of manipulation. it's just the way to enter in it that is slighty different. Woman are more keen to fall in the emotional spectrum while man in the recognition/gratitude spectrum. The majority of ISIS soldiers per exemple are fallen into a form of manipulation too , by joining a group in hope to give a meaning to their life.
And so on...
Well, depends. Female are smarter, and it actually work against them, most of them would think they are smarter than that and ignore the facts present in front of them.
The problem with man is they are mostly dumb and stupid, yes, it could be tamed sometime with material things but most male are dumb and stubborn, like talking to a child, and that is quite hard to covert if you are working in HUMINT.
But for me, I find that Female is more forthcoming with information you need, that is if you can get it out of them in the first place.
My point is nobody can take vacations to Syria, especially at that time. Just your travel destination being Turkey is enough to cause suspicion/questioning at the airports. Let alone actually crossing the border into Syria, will get you caught by Turkish authorities. But I agree with what you're saying, they couldn't have prevented it if they expected something else from a trip to Turkey. Nevertheless, I am sure there is active intelligence agencies all over Syria from all countries in both regime held areas and rebel held ones.
well, again, maybe, or maybe not.
The question is whether or not going to Turkey would raise a red flag, going to turkey itself would not raise any flag, especially if you get on a plane at the last minute, the intention is unclear, and we cannot assume people going to turkey would automatically mean they are joining ISIS. If that happen, they may as well cancel all flight in and out of a country.
If she have a mind to deceive the country in the first place, she could have beat the system as FBI will teach her some degree of anti/counter surveillance technique. Hence, as I said, if she intended to deceive the government, given a few days head start, it's impossible to catch her at that point.