I beleive I have seen your gooey brownish-red "dots", except in my case
it was on a wall in a closet upstairs, again under a shed roof. They
appear now and then, apparently either from the inside of the house
(depositing on the drywall) or from within the wall (diffusing straight
through the drywall). They slowly ooze down the wall a few inches until
I just wipe them off with a paper towel.

I have no idea what it is. As far as I can tell, the roof doesn't leak,
the wall is otherwise bone dry, it is not mold of any kind (it is truly
liquid), it doesn't damage anything, leaves no other traces, and
doesn't smell. The problem is localized to two small areas, about 1
square foot total, in a single closet.

Sorry I can't help, except maybe to say you probably aren't crazy, and
yes, the stuff is wierd.