These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Fridge Brilliance: Harrison Wells mentions that while Barry was in the hospital, his heart kept speeding up so fast the machines couldn't read it. A little thinking makes you wonder how he knew that Barry wasn't just flatlining. Thus, foreshadowing that he's from the future and already knows that Barry will become the Flash.
Fridge Horror: The Reverse-Flash is active, and has already killed Barry's mother.
They Changed It, Now It Sucks: The changes made to the Flash's costume from the comics have received some criticisms - namely the Chest Insignia lacking the white centrepiece; and that the character nicknamed the Scarlet Speedster isn't actually wearing his distinctive scarlet/bright red, but rather a darker maroon or burgundy. However, the final shot in the pilot reveals that in the future the Flash will have a costume that has these alterations.