You don't go through customs leaving the US and there is no requirement about how much money you take out. If you bring $10,000.00 or more back into the US you must declare it when you enter the US.
No I did not for the first part of the K-1 but I used a agent for the US Embassy part to arrange for background check, medical examination and helped with interview questions for her. They also arranged for the interview appointment.
We will have a prenuptial agreement that she has agreed to sign. Also she already has 2 houses and a good job with a pension and worked for the same company for over 20 years.