Sorry, I don't know what a schottky diode is, can't remember much other than the documentation for the ESC said I didn't need one on a 540 setup. I doubt I would be wrong to assume it is not just a relatively standard power diode with a fancy label and a high current capacity.
Regarding 10 3 amp diodes in parrallel - In an ideal world, all the 10 diodes will have identical forward junction voltages and the wiring will have identical near zero resistance. Because this isn't the case, the current will not divide evenly across the 10 diodes, so some diodes will take more than 10% of the current and some will take less. The end result is you will start overloading and burning out at least some of the diodes long before you reach 30 amps. I recall seeing a recommendation that involved setting up each diode with an resistor in series and then putting the resistor/diode sets in parrallel. This helps even the division of current between the diodes. I can't remember the calculations, and it was not for any RC related purpose.
I'm sure this all sounds way too complicated for anything you were thinking of so I doubt there is any point in trying to add to the details.