Sounds like possibly a clogged/leaking PCV. There is a couple passage ways that have o-rings between the oil housing and block. There could be oil bypassing the PCV. But I'm not an auto mechanic.

 

#1 - Fill capacity is 6.4?5 quarts. If you changed the filter, you need to fill it back up to the correct amount, otherwise, a flat 6 works perfect if you don't change the filter.
#2 - Oil pump is based on engine RPM, which means pressure is based on RPM given that flow is through an "unchanging" set of passages. If it drops and your oil light comes on, it means above that you're not triggering the light, which is normal. Worth a check to see if it is unusually low though and sitting just above the cutoff for the light as a normal engine can drop RPM and doesn't do that.
#3 - The fact that you lost 1.5 quarts over the last interval is concerning. It sounds like the oil you found on the front is probably the symptom. I agree with Jirv0id in that it sounds like your PCV/oil filter box is clogged somewhere and is pushing outward on the seals. That's usually what burns oil in our cars.
#4 - I'm not sure about your ticking issue. I have one that sounds like yours, nearest I can figure it is because either my VVT actuator is going bad or a VVT gear is going bad, but I'm not sure which. Nothing has gotten bad enough, and given the Ohm range acceptable in VIDA for the actuator, (something insane like between 2 and 500 Ohms), you won't get a CEL that it's gone bad, unlike commanded VVT timing that will trigger if the gear has gone bad.

 

Light came on again after driving highway speed and then stopped at light. After the car sat a while, I checked the oil and it is in normal range. I don't see oil leaking yet but I can smell oil but it may be residual from the previous leak. The exact source of that leak was not found after careful inspection other than around the PCV housing. Given the looks of the old filter element, the leak at the housing and possibly the sound; it is likely a failing PCV. I think I'll change the housing just because.

Since I was nervous about driving from work with possibly low oil pressure, I added some Lucas to thicken it a little (less than 1/2 qt). The light stayed off even after highway and stop. I expected the knocking (swirling?) noise to quiet if it was something like main bearings. However, it seems more pronounced. I am betting the at the noise is coming from the PCV housing also. It is subtle and might be more of a popping than a knock.

 

After replacing the housing, did it solve your issue? I'm having a popping noise coming from that area. This all started after a timing job and oil change.

 

I was back under the car today to change the transmission oil and inspected the PCV box from below. There is a leak still. I am not sure if it is the PCV box or the oil sensor though. I think I'll replace both when I get it apart.

 

I replaced the PCV housing today. I think the housing is still good. The previous owner had it replaced at some point but whoever did it, did not do a very good job. Two of the four bolts may not have been torqued properly and they did not clean the surfaces where it mates to the block. There was crud under the seal and likely the source of the leak. I replaced the two hoses while I was at it. I am surprised I didn't have oil leaking on the top of the engine. That hose was hard and slid right off the nipple. We shall see how it does from here.

 

I replaced the oil pressure sensor when I replaced the PCV housing. All was good after that.