Delete D1, the optocoupler and R2.
Use a VND14NV04 (or similar protected driver) in place of Q1.
Change R3 to about 1 Kohms. It now serves the input resistor.
You likely will initially bench test with no diagnostic feedback.
Implementing diagnostic feedback is best done just before or during turn-off.
The obvious way to implement diagnostic feed back is using an input pin to monitor the input of the driver. If you are outputting a high level, the input should be high. If it's low, the input is being pulled down by the protection circuitry.
Alternatively you can monitor that without using an additional pin. Change the pin from output high to input with pull-up and immediately read back the pin level. If it's still high, then the driver is operating normally with the internal protection circuitry being supplied their 100uA draw through the ATTiny pull-up resistors of about 25 KOhms. If it's low, the protection circuitry has pulled the input low and the 1K series resistor is dominant over the internal pull-up and circuit capacitance.
You might consider the LED2 activity indicator circuit. LEDs are generally robust with reverse voltage well over their rating (typically only 5V). Some circuits expose them to 120VAC through just a high value resistor. But to meet datasheet specs you'll want a diode in series. For automotive use you would want to move it to the 5V rail for consistent brightness, but for bench testing the 12V supply is OK. I suggest that you increase the resistance substantially if you are going to be using 12V.