To answer your last question....
When I get ready to cook on the uds, I pull out charcoal basket and shake ashes out. Then I'll just pour new lump right on top of the older lump. Then I might add some more wood, maybe not. Just depends on what I'm cooking that day. But I always leave the older chunks of wood in the basket. Never had any problems doing it this way. I cook often, so the older charcoal never sits long enough to go bad.
UDS, mini wsm, 22.5" weber kettle