THEME:   Y in a phrase changed to ING   
GOOD ONES:     Taking inventory at the Tropicana plant?  ORANGE COUNTING [Orange County]   
Boxer catching flies?  SHAGGING DOG [shaggy dog]   
Pierre's home: Abbr.  S DAK [I thought 
maison]   
Office component  EXCEL [I thought an actual office]   
Singer?  RAT      
BTW:   '60s-'70s Mets coach Eddie : YOST [he is better known as a top flight lead-off hitter]      
Seraphim and cherubim, to Giovanni  ANGELI [As 
angeli is not used in English, I'd go with "Actress Pier"]      
Grammarians' concerns  USAGES [the usage is USAGE]      
Big Apple news initials  NYT [the correct name of the paper includes THE]      
EINS, OESTE, EL NORTE, ALLO are not used in English.         
RATING:    
 
Three grins = Loved it; Two grins = Enjoyed it; One grin = A bit bland for my taste; One teardrop = Not much fun