So I'm trying to wrap up my engine build but I'm hitting a wall because I don't even know what exactly I'm trying to wrap up. It seems further I get, there's just more brackets, hoses, and connectors to put on. I need some help identifying a few electrical connectors, coolant pipes, and intake ports.

Hopefully a few of you guys with Subaru backgrounds can help me figure out how these work. I've tried the Subaru parts diagrams for some items but they have an annoying tendency to not show the whole system. My donor car was also missing a TON of these components for PCV and such so I'm working from nothing on that end and I have a hard time trusting any setup that was previously on the engine.

Picture #1: I have this solenoid valve that I'm not sure what it mounts to or what it does. The connector connects to a plug on the front of the engine harness but that doesn't necessarily mean it goes here. I also have this very small single wire gray plug for something here.
Front Small Connector and Solenoid.jpg

Picture #2: Where is the plug for this PCV hose? I'm really not even sure what this connector is for.
PCV Connector.jpg

Picture #3: I have an unidentified electrical connector near the throttle body but nothing within reach to plug it into. I think I may have a sensor missing on the top of the engine block but I have a better picture of the location in pic #4. Knock sensor perhaps? There's also these two small coolant lines, do they connect to each other as a sort of crossover?
Rear Electrical plug and small coolant connectors.jpg

Picture #4: Here is the location of what looks like a sensor port. I have it plugged with a bolt at the moment. It doesn't seem like it has an oil passage or anything but it has a machined flush mounting surface. Also, do these large coolant line ends go to the heater core? The FFR manual shows two lines very close to each other but mine are about a foot apart.
Heater pipe and possible engine sensor.jpg

Picture #5: Where does this small coolant connection go on the front of the engine? My donor had it capped like this and I can't think of anything it'd go to nearby.
Front small coolant connector.jpg

Picture #6: What does this port on the turbo inlet connect to?
Turbo inlet connector.jpg