I am sorry, but I am only qualified to give advice on cardiology issues. In general, weight loss is directed at taking in less calories than you use. There are no real gimmicks, just commitment to slow progress.
Extreme iron overload (a condition called hemochromatosis) is associated with atrial fibrillation. This is an unusual condition. I am not aware that less extreme iron overload is associated with atrial fibrillation
We do not understand this completely, but think that it is due to age related replacement of normal muscle cells with scarring - this leads to slowing of the electrical conduction in the atrium, which favors atrial fibrillation
I do not think that this condition has anything to do with your heart. It sounds like something you should take up with your internist/family physician
Atrial fibrillation does not go away on its own, in fact, it tends to progress (more frequent, longer lasting episodes) over time
There is no problem with taking atenolol and mexiletine at the same time
I am a cardiologist and electrophysiologist, and cannot speak with any authority on unrelated subjects. It sounds as though you need a good internal medicine specialist to help sort out all of these problems.
It is not possible to answer your question without more information. Some of the problems that result in risk of stroke are genetic, some are not. I would certainly recommend that your children attend to risk factors or conditions that lead to stroke (diabetes, high blood pressure, atrial fibrillation) and treat these factors aggressively
I am a cardiologist and electrophysiologist, and cannot speak with any authority on unrelated subjects. It sounds like a neurologic problem, and I would make sure that she sees a competent neurologist to find the cause of her symptoms, rather than just trying random medications
I encourage patients to exercise despite AF episodes. The problem is that exercise tolerance is reduced during AF for many people. I think it is still important to do whatever exercise best suits you though.