So you're paying business-related bills out of your bank account? If that's the case, then it's more of a matter if your suppliers will accept Amex as payment. If they do, you're golden (pun intended). Pay using Amex, then pay Amex through Bank. An extra step that's worth it. If you have $30k/monthly expenses, then you should really consider getting the Amex biz gold (if you don't already). $5k of spending within three months yields 40k Amex points (through a referral).

As far as churn goes, typical response is apply, hold the card for 6 months, cancel and wait 6 months before re-applying.