Notes by Ismael Velasco:
If you are deepening on the Qayyumu'l-Asma, you might want to read the Guardian's brief codification of its contents in God Passes By. Although it looks like he is only remarking on it more or less casually, a careful comparison of other summaries of Bahá'í scripture in God Passes By with the original texts reveals rather that the Guardian is providing a systematic and highly condensed overview of each of these books. Also, Todd Lawson's paper on the Báb's approach to Qur'an interpretation (photocopies circulated with the student pack) has an analysis of the Qayyumu'l-Asma. If you are really keen, you can find a translation with commentary by Todd of one of the chapters of the Qayyumu'l-Asma at bahai-library.com/bab_qayyum_asma. This will give you a further flavour of the original and place it in a broader context.
On your question:
"The Quayyumu'l-Asma seems to be declaring the Báb's new Revelation as the new Day of God and calls upon the peoples of the earth to recognize Him and to turn unto the Gate. When Mullá Husayn heard/read this, it had tremendous a impact on him, since he was already seeking the Promised One. Do I have that about right?"
I think the answer is a subtle one, and one that has exercised scholars considerably. In the same way as Bahá'u'lláh's writings previous to His declaration in 1863 and really until His proclamation in Adrianople have clear ambiguities regarding His station, so the early writings of the Báb lend themselves to a range of interpretations. While it seems most likely that Mullá Huseyn, in the context of His stay with the Báb, read the Qayyumu'l Asma with a full sense of its messianic significance, it is also evident that others read in the same book more limited claims to being an intermediary for the Hidden Imám, or even merely as an inspired successor to Siyyid Kazim.
I see in this approach, common to previous Revelations, an intentional ambiguity whose purpose is to build as wide a bridge as possible while antagonising as few people as possible, in order to build a broad based community of followers (believers might be too strong to cover the range of initial relationships to the Báb) in preparation for the eventual full and clear proclamation which will divide those who believe and those who don't and which is associated with the designation Day of Judgement. Until then, people relate to the revelation at various levels. Some cling to passages that seem to indicate the Prophetic station of the Founder (highlighted in Selections from the Writings of the Báb), while others cling to passages that indicate merely an exalted spiritual station as a prelude to the final Advent (many of these followers left the Báb when they became aware of the full extent of His claims), and some to those which indicate merely an intense or exaggerated traditional piety (among whom were a number of non-Bábí sympathisers). Eventually, as the following grows, antagonism rises, and the measure of revelation increases to unveil ever more majestic claims, people fall away or cling more firmly, and a community emerges around the recognition of a new Prophetic cycle with the authority to "do as He pleaseth". The Qayyumu'l Asma belongs to the early, capacity building phase, and thus provided a platform for a range of relationships to the Báb which would steadily diminish in theological variety as the Báb's claims grew, culminating in His proclamation in Tabriz and Tahirih's unveiling at the conference of Badasht.
Notes by Todd Lawson:
The concepts of the Báb and the Imám, from a historical perspective, come to the Faith via Shi'i theology and "Imámology" — a rather ugly word, but one with an important technical meaning. It is the cognate of the word "Christology".
The Family of God (consisting of his 14 most immediate family members) are considered to be "protected by God from making mistakes". This protection is called 'is.ma in Arabic and esmat in Persian. Their protected status is indicated in one of the many different honorifics used to refer to them: al-ma'su:mi:n. They are ma'soom. That is the quality of 'is.ma is conveyed to them actively — they are the passive recipients of it (not the active originators of it) from God (the only real Actor/Agent in the cosmos).
It holds that these Persons are incapable of making an error, whether the error is in the moral and ethical realm or even the scientific realm, according to a strong theme in Imámology. This 'is.ma is sometimes translated as Infallibility and sometimes as Impeccability. But, in terms of practical piety it means both.
To respond to Ismael's question, the Shaykhís held that there was no difference between the Prophet and the Imáms and Fatima. All were equally Infallible and equally manifestations of the divine. This is dramatized in the language of the Qayyum al-asma. The Báb ostensibly claims to be merely the Gate to the Hidden Imám, but throughout the work it is clear that he considers himself to be participating in the same charisma as the Holy Family. Certainly his readership saw this as well. Here the field of grace Tom speaks about represents a spectrum of intensity of holiness/being/light/love. There is no difference in kind, only in degree. And at the level of Bábíyya, the degree, as far as mere mortals are concerned is immaterial. 14 flames of the sacred fire.
An excellent book for this course would be M.A. Amir-Moezzi, The Divine Guide in Early Shi'ism. Since, as is pointed out in the article by Smith and Momen, the Bábí Movement is utterly Shi'i, it would be useful to investigate some of the more prominent motifs and symbols of it. Indeed, both the Báb and Baháulláh were Shi'i Muslims. More importantly, their original audiences were Shi'i Muslim.
Abdu'l-Bahá has also said that the teaching about the Hidden Imám , the 12th Imám, was in large part a pious fraud. Perhaps Moojan can give us the reference? This would have scandalized the Shaykhís in one way, and in another perhaps not.
One of the controversies in the academic study of Shaykhism is precisely: did the Shaykhís teach an actual parousia on the historical plane of the Hidden Imám, or was their teaching mainly on the order of esotericism: the Hidden Imám will appear to the true believer in their heart, or in the realm of the creative, spiritual imagination, the so-called "world of images" ('alam -i mithal).
Ismael is, in my, view correct when he speaks about the Qayyum al-asma as being susceptible of a number of interpretations. In this work the Báb can be heard speaking with the voice of Alí Muhammad or the Báb, the representative of the Hidden Imám, or the Hidden Imám himself (i.e. a manifestation of God) or God. Or all of these "at once" (as it were). This is explained to some degree in an article I wrote for the Balyuzi Volume some years ago in which I explore the titles "Gate" and "Remembrance".
As to the objection that the Imáms are considered to be of lower rank in Shi'ism, this is also true. Recall that at the time of Shaykh Ahmad a vigorous battle for authority had just been lost. The legalist rationalist group had won and the intuitionist, literalist group had lost. For the legalists (mujtahids) it was important that the Imáms have less authority than the Prophet. So they emphasized the differences. For the other group, called Akhbaris, all of the statements of the Imáms, all of them, were considered scripture.
In order to gain an understanding of the authority of the Imám I suggest the Friends read the series of Sermons recently translated by the great scholar Khazeh Fananapazir. These are located at bahai-library.com/Translations. It is essential, in fact, that the students of this course read at least one of these Sermons, any one will do.