Two further thoughts.
On the villains- I guess what they are trying to say with Capt. Cold and Heatwave and how they relate to their respective weapons is that the guns mirror their personalities. One is stone cold, and the other a hothead. If not for that, then it seems like literally anyone could become their characters just by picking up the guns.
And one more fashion observation on Felicity- Did anyone notice that in the short jump from the scene where Barry first showed her his speed to the one where he brought her to STAR Labs she changed outfits? Didn't seem to be any particular reason why.