Your sixth photo from the bottom shows the "silver" coolant cross-pipe that crosses the front of the block in the vicinity of the oil pan. I notice the coolant drip underneath the water pump boss that the pipe plugs into. There's an o-ring behind that - could be leaking there. I'd lay a big sheet of clean paper down under the engine, start it, go inside for a coffee and checkup on audizine : ) and then go out later and see if you can see any telltale on the paper. If not, sit in the car for ten minutes at high idle, say 2000rpm, and see if that produces anything. You want it to run down without being blown around by air movement (fans will obviously mess with that a bit but you could leave the hood open to reduce the impact.