I've had a few moments when I've thought, "Gee, I think Infriga would've been better than Fozare in this scene." Ever have those moments? I'm sure there are reasons for each--Fire isn't best here, could hurt bystanders...Force is better...As we see Dresden develop a bit more finesse with magic along the way, I think it would be cool to see his spell-casting become even more nuanced.
When he and Asher go to the party to get Valmont, I thing Infriga would've been cool instead of Fozare in dealing with the initial appearance of the Fomor and the octokongs.