1)
Which Olah is the Torah currently referring to, and in Pasuk 16?
1.
Tosfos (in Beitzah, 20a, DH 'Vayakrev es ha'Olah"): The Olah currently under discussion is the Eil ha'Olah of Aharon, whereas that of Pasuk 16 is the Eigel and the Shor of the people.
2)
Why did Aharon's sons need to hand Aharon the blood (in a basin) for him to sprinkle?