Can maxillary mucous retention cysts cause my head to feel unclear/stuffed-up/cloudy along with tinnitus and mild imbalance. There is no sinus pain.

Probably not. Maxillary retention cysts are common, in some series up to 40% of individuals. In the vast majority of cases they are free of symptoms. When they cause problems there is usually a history of maxillary sinusitis, maxillary or dental discomfort, nasal congestion. It is unlikely that your symptoms are related.