15MHz photodiode PCB, feedback requested
My first thought is that you can get rid of R7,R9,C3 and C4 altogether. Your op amp has 1 pA bias currents, for heaven's sake. The input offsets produced by bias current and feedback resistance amount to about 25 nV. 

However, I'm extremely dubious that you can get the response you want. You're only talking about excess gain of 5 at 15 MHz, and that is not remotely adequate. Modelling the circuit as having 2 pF input capacitance, it's possible to get 15 MHz performance with a 2.5 k feedback resistor, but it is wildly sensitive to the value of the feedback capacitor, and that is never a good sign. 

Putting a guard ring on the PD seems a waste of time, since you're clearly not operating at extremely low currents, and it does somewhat increase input capacitance.