OP, I got FR'd on my 9-10 month old Green after trying to charge $2700 in legal fees when forming a new biz. While that month had my largest balance, a call to an Amex CSR revealed that the legal transaction resulted in the FR. Moments prior to the charge, I checked the spending availablility on Amex's website and there was enough to support a $2700 charge.
I say just spend it anywhere and everywhere. This paranoia of getting in trouble with American Express is crazy. I use my amex everywhere. If they did AA on me one day I'll just move elsewhere.
I'm the 'use it as you need it' type individual .... but if you go nuts right after you get the card and use it at pawn shops, brothels (where it is legal), the horse track, and other such places you might raise their eyebrows. I've had AMEX for 30 years now and have never had any issues or problems worldwide, but I don't use it for day to day stuff like McDonalds, that's what cash is for. Use it with a bit of sense and you'll have no problems.