Shemini. Nadav and Avihu's Sin

This week’s parsha depicts the excitement of the Mishkan inauguration and the shock of the deaths of the new priests, Nadav and Avihu, as:

“Each took his fire pan, put fire in it, and laid incense on it; and they offered before the Lord alien fire, which He had not commanded them. And fire came forth from before the Lord and consumed them” (Vayikra/Leviticus 10:1-2)

What did Nadav and Avihu do wrong? Some say they were drunk (Rashi) on the basis of the warning, a few verses ahead:

“Do not drink wine or intoxicating drink, neither you nor your sons, when you enter the sanctuary and you will not die.” (10:9)

Other opinions are offered by the Midrash (see Vayikra Rabba 20:6-11) drawing on the language of the verse:

“Before the Lord” - That they entered the Holy of Holies,
"Alien Fire" - Brought from a profane source, outside the Sanctuary
“Each took” - that did not consult one another”

So ... what do you think

“They did not consult one another” – If they had consulted with Moshe and Aharon, or even with a friend, would they have made this mistake?
Can you share an error which you could have avoided if you would have got some sound advice?
Why do we sometimes shy away from seeking advice?

In the final analysis, the precise crime is undefined. One phrase seems to encapsulate their sin: “That He had not commanded them.” Put simply, they didn’t follow the rules. Why not?

“And the sons of Aaron took: They too were bound up in the joy of the occasion. When they saw the “new” fire (from God) they acted to add love to love.” (Sifra)

What is the meaning of this esoteric phrase: “they acted to add love to love”? In this reading, Aaron’s sons were moved by the noblest of motives, thus their given title - “sons of Aaron”. They were excited by the event of the Temple dedication. They saw God’s love of Israel as embodied by the fire that descended from Heaven to consume the Offerings (see Lev. 9:24 and see the parallel phrase “And fire emerged … and consumed” between that verse and 10:2). They wished to reciprocate, to repay God’s love with their love; God’s fire with their fire. They sought to emulate God, to dedicate their own religious act. Their motivations were the highest of the high. But their act was wrong. It contravened the regulations of the Sanctuary/Mishkan.

Rabbi Samson Raphael Hirsch (1800-1888) comments:

“More than anything else, [the biblical text] stresses that God had not commanded them. .. No place is allowed in the whole service of the offerings of the Sanctuary for subjectively doing just what you think right. ...Proximity and getting near to God is achieved by way of obedience, by compliance with God’s will … This is one of the point sin which Judaism and Paganism go in diametrically opposite directions. The pagan brings his offering in attempt to make the god subservient to his wishes. The Jew with his offering, wishes to places himself in the service of God... Not by fresh inventions, even of God-serving novices, but by carrying out that which is ordained by God has the Jewish priest to establish the authenticity of his activities.” (Hirsch on 10:1)

Please discuss.

Rabbi Hirsch is making quite a sweeping assertion here.

Is it only in the Mishkan that “fresh innovations” are unwelcome, or in all of Judaism?
When does one have to follow the rules of Halakha, and where is there room for innovation?
What are the advantages of letting your personal religious passions express themselves in ritual?
Does Judaism have room for this? Are there dangers in this? Is Jewish tradition wide enough to accommodate free expression and “compliance with God’s will”?