Can anyone identify these pieces?
The first piece is 424 Technic Hub / Handle 1 x 1:
It's actually pretty rare, only appearing in 9 sets from 1995-2006, and likely to stay that way as it has a similar newer counterpart, 18654 Technic, Pin Connector Round 1L which probably replaces it.
I cannot identify what those bottom black inverted slopes are though. It looks kinda like Wedge 6 x 4 Triple Inverted Curved, but without the middle 2 studs up front.