Let's redraw the schematic in a more conventional fashion. It should read well with some sort of input to output logic from left to right (which you had managed) and voltages decreasing from top to bottom (which you hadn't). Use GND symbols where possible to eliminate wires and you can do the same with the positive supply if it helps.
simulate this circuit – Schematic created using CircuitLab
Figure 1. Circuit redrawn and R2 added.
I've also split the circuit into logic - the ESP32 and relays - and power - the motor and switching circuit as, to some extent, they are separate. A few things now become clear:
- The relay coils are in parallel.
- D2 is redundant. D1 will protect Q1 from both relays.
- Q1 is operating as a common emitter switch. It needs some base current limiting so R2 has been added.
- The motor polarity reversal scheme should be a bit easier to follow.
- M1 is switching the motor negative (for your PWM control).
- The IN5408 is providing freewheel protection for M1.
The RFP30N06LE is designed for switching with a logic-level gate signal so it should be fine.
Is the diode labeled motor diode protecting my MOSFET from potential damage?
If the motor is spun my some force do I need any other protection to prevent this circuit from being damaged?
That depends. Force won't matter but speed will as the output voltage will be speed dependent.
- With the relays de-energised as shown in Figure 1, if the induced current flows from left to right in the motor it will, in effect be shorted out by Motor Diode and a high resistance to motion will be felt.
- If spun the opposite direction then the motor voltage will rise with the right side negative. Now the left-side is held at +9 V by the battery. As the motor speed increases the right side voltage (and that on the drain of M1) will decrease from +9 V to +8 V, etc. If you keep speeding it up it will eventually drive the drain of M1 negative with respect to the battery. At that stage the built-in (intrinsic) diode between the source and drain (see the first page of the datasheet) will begin to conduct and protect M1. You will now be charging the battery which may or may not be OK, depending on chemistry and duration of this condition.