Sidewinder, Yes, the "oil mist" from the center of the breather is lubing the timing chest, but I think "oil Hurricane" is a better description, with a quart of oil per minute mixed with air coming up through the gear.
As for the case joint, that may not be directly related to the new pump, as it leaks standing still. The joint weeps just sitting.
Interesting theory on piston failure due to heavy oil. I won't say it isn't so, I never ran multiweight until I had switched to the sporty pump. Then I saw no difference in oil pressure when warm. But you do have a point that the oil tank doesn't get hot with the stock setup. I'm glad it works for you.
As for guide wear, mine have been loose for years and I hadn't changed them because at first they weren't available, and I didn't realize the importance of a good fit on a flathead 'till recently.
There's more on the oil pump stuff on my website, http://www.freewebs.com/dicky_linn/thir ... typump.htm
This is the latest conversion, using the stock oil pump mounting holes in the engine case.
Earlier versions required moving the stud mounting holes in the engine case.