Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
You will be OK. When connecting between AA and a oneworld carrier on separate tickets, AA will connect you in the event of a mis-connect.
If you have -- or can get -- some BA Avios, you could get the RDU-ORD-RDU legs for far fewer miles than what AA will charge you.