Nikhil,

Your reasoning is excellent. From your careful deliberation, I can see the hard work you've done in this area. But I still have some different opinions on this issue, which I'd like to communicate with you here. 
First of all, I appreciate your demarcation of conceptualism and the commonly known example of hammer in Heidegger's philosophy. The point here I want to argue is that, since you concentrated on the contemporary debates which concerning Heidegger's thoughts, you have not considered very seriously about the inner links between Husserl's phenomenology and Heidegger's ontology.
 
Husserl once mentioned in his Logical Investigations (Logisch Untersuchungen), truths are what they are irrespective of whether humans grasp them at all. The truths exist in "being in itself" (An-sich-sein), this concept, later which is famous in Sartre's Being and Nothingness. To speak more clearly, these truths are formed in those ideal unities. Husserl's idealities refer to numbers, logical entities, pure meanings etc. Husserl insists that ideal objectivities are given through essential seeing/ essence inspection (Wesenserschauung). So far, it seems that Husserl is someone like a conceptualist as such you mentioned. But the key point is that he didn't proceed his phenomenological research in a naive manner but worked it out in a complex structure, which could not be named as simple stages (one or two or more). The given of hammer itself through essential seeing can be simply viewed as one stage, however, this one stage is not a strictly sensed "stage", which we cannot generalize into a kind of psychic act for Husserl rejects using Brentanian descriptive psychology in his later works.

Heidegger, of course, has undertaken so much from his teacher. To a large extent, Heidegger further apply Husserl's phenomenology into his own ontology, although this sort of application more or less breaks Husserl's original stance. From Husserl's Wesenserschauung to Heidegger's Sagen, we can not only see the correlation between the former and latter but read out the great gap as well. Both of these two philosophers want to reveal the secret of the truth(s) in their heart, but they act out in different theoretical world. If we trace Husserl's thoughts back to Logisch and explore Heidegger's meditation towards Dichtung, we will find out that "being" in these two relevant theories refers to the same but performs quite differently. Heidegger's  "being"  more and more tends to Laozi's Tao, that we can see very clearly in his later works, also in his Being and Time we can dig out some proofs. In this sense, a kind of eastern living realization replaces the commonly acknowledged perceptual experience in Heidegger's philosophy that the former is both metaphysical and practical and the latter is philosophical and psychological.

Surely, the above argument is quite general but I think it can represent my basic ideas concerning this topic.