Is it possible to have no symptoms from alcohol induced gastritis or a bleeding esophagus?

Yes. Slow bleeds can occur without much symptoms. However, often there are symptoms of burning, gerd, nausea noted.
Not likely. Bleeding implies blood loss into gut that results in black tarry stools. Gastritis implies inflammation, swelling and irritation which would lead to stomach pain, indigestion or abdominal discomfort. If you believe you have a drinking problem please talk with your doctor or drug/alcohol counselor about it.