Does an enflamed bladder lining cause overactive bladder?

Possibly. Inflamed bladder lining can be due to infection, irritation, inerstitial cystitis, etc. Any of these diagnoses may lead to overactive bladder and more frequent urination.
Yes. Anything that irritates the bladder will cause frequent urges of urination. Also, changes in the acidity of the urine, caused by the diet and /or medications can also contribute to such symptoms.