I don't think you did damage to the EHA since you can't adjust those. Since you said in your original post that you close back up whatever you tried to adjust(most likely the EHA), you can retighten the two screws and start the car and check for leaks. You can leave the air filter housing off if you want. If there is a leak, its probably gonna come from the two small o-rings between the EHA and the fuel distributor. Easy fix. Good luck.
To answer your question on the fuel gushing out, it is residual fuel but still under pressure. You ca relieve some of the pressure by opening the gas cap.