Q1: Aaron wasn't qualified to touch the offerings until he had been consecrated. Why could Moses?
Q2: Moses temporarily took the role of priest in the ordination of Aaron and his sons. How was this possible?

A: In the wilderness Moses acted as both king and priest to the people. Like Melchizedek and #yeshua. Unlike Aaron, Moses had spent months being purified by the Divine Presence. He was consecrated by God's Fire, God's Grace, and his own continual obedience. He wasn't allowed to be a priest in the Tabernacle, but he could be a consecrator of priests.

Leviticus 8:27-29