You definitely have to clean it. Just looking at all that oil, the source will be hard to find and it could be coming from multiple places. Replacing the AOS and filler hose are good ideas. It also would be good to replace the spark plug tubes and o-rings while you are working on it.
Here's a few pics from the gallery of leaks I've fixed on some of my 986s:
RMS and IMS seal leaking. Oil at center rear of engine and some reaching the pan if not wiped.
AOS hoses and tubes leaking:
Spark plug tubes:
