I got the idea I should replace the CVT fluid.  In the process of removing the housing for the high pressure filter, I encountered a stripped T-40 torx fastener.  Being determined to change the filter, removing the screw required a bit more effort than expected, here's what I did:

1. Grab outside, attempt to spin (failed...)
   The tight position of the bolt didn't give me enough room to grab it by the top and spin.  If there wasn't so much other stuff in the way, this might have worked. 
2. Screw extractor (failed...)
   I happen to have a set of screw extractors.  They work by drilling a pilot hole and using another bit with reverse threading.  When run in reverse to remove the screw, the bit digs into the metal, providing enough friction to wind the fastener out.  The hardness of the metal used for this screw made it impossible for the reverse head to grab into the metal.  I tried several different sizes, all with the same result. 
3. Decapitate, wind out remaining stem of screw (worked!  jk, this failed too)
   This is accomplished by running a drill bit through the center of the head, making a hole larger than the stem of the screw.  When the drill reaches the stem, the head will have nothing fixing it to the stem and the remaining screw can be wound out once the part has been removed. The hardness of the faster made this slow going, to the point where the metal screw was being polished more than cut.
4. Cut head to fit slotted screw driver (victory!)

   Used flat-head at 10 and 4

   
   Should have done this from the start.  Cut a slot on a radius line in the head of the fastener, use slotted screwdriver to remove.  I didn't have an easy way to reach the bolt in question, but I did have a Dremel, I just needed the right cutting tool. The part wasn't accessible with a cut-off ring, but I could reach it with a plunge cut bit. Such a thing exists for Dremel tools, even rated to cut hardened metal: the 9903 Tungsten Carbide Cutter.  At high speed, the bit chewed thought the metal no problem. With enough material cut away to fit a large screwdriver, I was able to get a twist on the bolt and break it free.  Obviously, this method sacrificed the fastener, I'll need to get an approximate replacement at the hardware store. 

So, it was dirty...

Broken Transmission Cooling Lines

When I tried to remove the lines from the cover of the filter casing, they wouldn't budge.  I had trouble reaching them from the top of engine to pull upwards, so I struggled from the bottom and when the first line came out the second, after a light tug, snapped.  Or maybe not.  Considering the amount of oil around the part, something was leaking and it wouldn't surprise me if this was in some nearly broken state at the start.  At least my theory assuaged me as I went about searching for a new transmission cooling line.

Finding the Part, found a new vendor

Amazon and RockAuto didn't stock this part, so I looked at the official Ford parts site ($107, next day availability) to get the part number and they searched to see if I could save a buck or two.  I found the part at Tasca Auto parts for about $75 + $8 shipping.  I saved a few dollars because I could afford to wait a few days.  At Tasca I was completely surprised by the service: I sent some email to double-check if I was ordering the right part and somebody got back quickly asking for the VIN for verification and then replied with the correct part number I needed to order.  I would have ordered the wrong part without checking with the vendor, so I'm glad I did. I'm guessing the customer service department at Tasca saves a huge amount in re-stocking costs by making it easy to verify fitment by VIN.

Extraction...

Part of the old filter was stuck in housing

Note larger opening on filter, at first I thought I had the wrong filter.

Removing the filter was done with a hook pick and a light tug. Once removed, I checked if the old filter was like the new filter, to make sure I had the right replacement. There was a difference in the opening where the filter interfaced with the transmission.  As I was muttering various vulgarities, I looked in the filter housing and saw the opening was bigger as well.  Did I get the wrong filter? That's when it became apparent the new filter was slightly taller than the old and didn't have an o-ring at the top. Ahhh...  I realized the top of the old filter separated from remainder and was still in the transmission.  I reached inside and with a pick removed the cap from the prior filter and new one fit perfectly.

Just so dirty...

After use, on expects filters to look dirty because... they catch dirt. But the old filter looked particularly bad. This is were I started to worry a little because this tells me the transmission wasn't completely serviced in a while.  Maybe the fluid was drained and replaced, but the filter looked particularly worn. Two other things to note: the outer cloth around the filter and that it was constructed of metal instead of plastic like it's replacement.  Not sure if any of these differences affects filtering performance.  For what it's worth, the replacement part is an official Ford replacement "kit", costing $32, comprised of filter and o-rings for the filter hosing and cooling tubes.

Not really sure why the old part has oxidizing

While we're looking at old versus new, taking issue with the poor state old part, the filter kit come equipped with a little tube with some rubberized coating.   This tube transports fluid from the transmission to the housing, so it's a good idea for it to be in working order.  Note the material around the outside of the part, on the inside (not pictured) I didn't see any corrosion and the part felt sturdy.  This tube sits between the filter housing and transmission case and should be well protected by both, I'm wondering if the filter housing wasn't well seated thus contributing to the oily deposits in the area.

Installing the Filter