Just a few things. GOES is the online registration system that you use to apply for Sentri or Global entry. Global entry allows you entry back into the US from any country so you can use it in the Sentri lanes as well. Global Entry is cheaper at $100 dollars but you pay it up front and if you don't pass the screening then you are out the money where as Sentri you pay the $25 application fee and if you don't pass you are only out the $25. Once you recieve Sentri then you pay the remainder of the cost.
Just because they issue a Sentri or Global entry card does not mean that they can not pull it from you at any time. If you get a DUI or have other problems once you have your Sentri card I am sure they monitor those things. You need to keep your information updated on GOES. If you apply when you are living in the US then move to Mexico you better change your living address to be in Mexico.
One example is when I was crossing on foot one day via the Sentri Ped line. The line was pretty long maybe 20 people and there was an agent coming from behind asking people to step aside. One Mexican lady was giving the guy lip service for some reason. They argued back and forth for a few minutes. He finally told her to follow him and he was going to revoke her Sentri. At that point she burst in tears. He escorted her directly to secondary and I don't know what happened after that.
They look at combination of factors that have been discussed in this thread to grant you a Sentri or Global entry card. I would venture to guess if you have any checks in the high risk category then you will be denied. There are plenty of senior citizens who have Sentri and do not work but I am sure they are able to show they have money in the bank or invested elsewhere.
