I actually don't think that you will have any trouble with the exam. Most of it is just basic common sense based on what you already know. Have you looked at any of the review books?
I don't think that things are going to revert back, they may only get even stricter. Right now Visa Screen is only required if you are applying for a visa on your own. If you are getting a green card because of marriage, etc. or because your spouse is getting one, you do not need to go thru Visa Screen at the moment. I think that is going to change, especially because of the language requirements, if nothing else.
Any nurse that is actually working in nursing on a daily basis should not have any problem at all with the exam. If you have been away from nursing for a long time and do not do any of the preparatory questions then you can have a problem.............
Good luck if you decide to sit for the exam. Please let me know what you decide to do.....I know that you have been thinking about it for quite awhile.
I definitely recommend that you take NCLEX and not CGFNS.