You were right about the "nipple crack". I pulled the hose tonight. The nipple was cracked at the seam with the radiator. Because I'd moved the hose some before, it wasn't wet where it had been and that threw me off. I applied some 5 min. epoxy and held the crack closed with a C clamp. When it dried, I covered it with JB Weld liquid steel, wrapped electrical tape around it all, slipped the hose back on top of the now taped nipple and tightened it down. Going to let it cure overnight before testing it by driving to work tomorrow AM. I have my fingers crossed.
As for the rest, I paid closer attention driving home from work. You know the noise the tires make when you hit those speed bump lines on some toll roads before the booth? That Braaaaaaap sound? It is a similar noise but MUCH more subtle. You almost feel it more than hear it. It is most noticable between 45-50 and disappears above 60. Because it comes and goes from zero to 45, odds are higher that it isn't a motor mount. But with the mess of antifreeze I made on the floor, I wasn't up for crawling underneath.
As for the thunk/clunk, paying attention. it does it every time I hit a sharp bump at low speed like at the base of my driveway and the 1 1/2" lip between the driveway and the garage floor. Clearly something in the suspension. I'm determined to find it but after the radiator tonight, having to fix that the accessory key they made me today locked the trunk, but not unlock it, and sitting in the car, notice that the dash cluster seemed a might off and pushing on it had the glass fall into my hand...I'm taking a break.