I have barrett's esophagus, do I have a greater risk for cancer

Yes. Barrett's esophagus is associated with a higher risk of cancer, specifically esophageal adenocarcinoma. However, the risk is still low, and most people with this condition do not develop cancer (less than 1%). Caucasion males who smoke are classically the ones with the highest risk. http://digestive.niddk.nih.gov/ddiseases/pubs/barretts/#3.
Yes. Barrett's esophagus represents chronic irritation of your lower esophagus by stomach acid reflux. Patients typically report frequent "heartburn." this chronic irritation is thought to cause the increased risk of developing esophageal carcinoma in barrett's esophagus patients.