Middling 
Professional pitcher? ADMAN
Tip for a writer? NIB [must be an old writer]
Plot device? HOE
Theme: Words in phrases that could go before “in the middle”
Like this answer’s position, and {theme} INTHEMIDDLE [center of the grid]
RATING:
Three grins = Excellent: Loved it; Two grins = Good: Enjoyed it; One grin = Satisfactory: A bit bland for my taste; One teardrop = Unsatisfying: No fun
