I only see the lower left flipper fire when the ball is launched, not right. Try swapping the flipper board connections between left and right flipper and see if issue stays with same flipper or moves to other flipper.

Upon inspection of the schematic, I see these are on the same connector, so not easy to swap wires. Do the LEDs on the flipper board turn on when the flipper fires? If yes, inspect flipper button switch and EOS switch. If no, test transistors or replace flipper board.

If the flipper button switch is stuck closed, the fuses shouldn’t blow as the flipper board should send the hold voltage and not the power stroke voltage, the fuse should only blow if the power stroke voltage is held too long, and this is controlled on the flipper board based on input from the EOS switch and some onboard logic/timing circuits.

Yes - the two lower flippers are "Coil A" and "Coil B" in the schematic, trace these back and see, there are a lot of them. Typically it's the TIP36C that fails first, those are Q3 and Q10. If the flipper board LEDs don't come on and your flippers flip, there is something on the board that is telling them to flip erroneously, unless you have some sort of wiring short as suggested by eyeamred2u.

Congrats!