[cre]

Personally, I'd replace that filter. It looks rather threadbare which is unacceptable. I've never seen them in any color other than red either... They may have been washing it in bleach which would have contributed to the degradation of the filter medium.

My preference is either Apex'i or AEM... I've heard really good things about Amsoil's EaO filters too, but I have no experience with them. You will need a different adapter for any of these to mount to the AFM.. You can get a simple adapter on eBay for just a few dollars. I would use a silicone coupler and a piece of pipe to put the filter out of the engine bay below the headlight.

The oil around the spark plugs is most commonly due to leaking valve covers. If it gets past the sealing boot of the plug wire it'll cause misfires and loss of power.

The O-rings on the outlet side of the injector aren't going to kill anything if they're hard. They're an air barrier. They prevent pirate air from entering the system there (or escaping when the manifold is under pressure in a turbo engine). If you can hear air hissing then the leak is large enough that it should be addressed... but on a relatively stock N/A I wouldn't sweat it.