Can acid reflux give the sensation that food is going down slow?

Yes, But it's important for you to make an endoscopy cause acid reflux can make the esophagus inflamed and then narrows, esophagitis can lead to this symptom.

Yes if the reflux is chronic and has made a stricture or narrowing of the esophagus. Could also be a condition called eosinophilic esophagitis, which is an allergic condition of esophagus. May need further evaluation with upper endoscopy.