[Black Hills Rider]

Possibly a crack in the injector plastic body. You need to find exactly where the fuel is coming out of to be able to correct it. Otherwise, it's just throwing guess parts at it. The O-rings on the injector look fine and I did not think that was your problem from seeing the picture. The "gasket" terminology is because it is the sealing area for the outside. The O-ring terminology is because that is the sealing seal from the inside.
Correct - most of us would just call them "O-rings". But being an aerospace engineer that terminology is what I am used to in diagrams.

 

[Black Hills Rider]

You might be able to use the tool checkout at Autozone or one other parts stores for an injector pressure checker - Not sure. it's just an idea for you to look into.

I doubt the pump is over-pressurizing. Far too much liability on a fuel related part to not have at least some decent quality control. As for the seal - It looks like it has the seals in the picture that are normally on an injector.

 

[Black Hills Rider]

A very slight crack can certainly be a spray when under pressure.

 

[Black Hills Rider]

New injector time. You pretty much have eliminated every other option.