1) Do you think that the empty tomb and any type of subsequent appearances would have been adequate to result in the use of “resurrection.” (i.e. did the appearances also have to have the impression of physicality?) And if you think they had to have the impression of physicality, do you think that this would not be sufficient to account for the use of ‘resurrection’ without the empty tomb? (Not that both could not have occurred for double confirmation).
I am inclined to believe that the appearances likely did give some kind of impression of "physicality." But I submit that this alone was more than likely not adequate to give rise to defining what had happened to Jesus as "resurrection." One thing about visions is that they can appear and even feel physical. After an interesting survey of modern day visions of apparitions Dale Allison makes this point:
"Most apparitions of the dead seen during bereavement are not, in the usual sense of the word, 'ghosts' (which is why the bereaved rarely use that word of their experiences). Apparitions instead commonly appear to be just like real human beings. It is accordingly often their odd arrival, or their sudden disappearnce, or their identification with a deceased individual that gives them away. Time and time again people not only hear and see apparitions: they even touch them. (Allison, Resurrecting Jesus, p. 290.)
Though Allison's study was in the context of modern day visions, I think the same was true of late Antiquity. Visions could have seemed very real, and physical to many people, even to the disciples. On this score, then, it seems necessary for there to be more than just visions to betoken their language of "resurrection." Thus to answer your question, even granting the physicality of the visions I do not think this would have been sufficient to give rise to the belief that God had raised Jesus from the dead.
2) How big of a role do you think Jesus’ more apocalyptic teachings and actions had on the disciples and their subsequent use of “resurrection” for the post-crucifixion appearances?
Most likely, Jesus' apocalyptic teachings and actions did have an impact on his disciples. However, even granting this influence, since Jesus probably spoke of his vindication as occuring during the general resurrection of the dead it does not seem plausible that solitary visions taking place without an empty tomb would cause them to assert that Jesus had been raised. I suppose it may be a possibilty but it's certainly not probable. Yet if we allow for the visions and belief in an empty tomb then the context of an apocalyptic setting provided by their teacher would definitely have provided a strong impetus for believing that Jesus had been raised from the dead.
3) Do you think the disciples’ use of resurrection was similar or the same as Paul’s use of the concept “first fruits of the resurrection”? With this phrase it seems to me that Paul is expanding the concept of resurrection from the view of normative second Temple Judaism. And it’s my impression that he felt comfortable doing this because of the soon to come general resurrection. Doesn’t “first fruits” have a temporal connotation? Wouldn’t he have been less comfortable using this phrase if he knew no general resurrection would occur for the next two millennia?
I think that the disciples' and Paul's use of resurrection were very similar in that both believed that Jesus' resurrection had precipitated the end of this age. Thus the phrase "first fruits" is an adequate metaphor that conveys this understanding. But since the giving of the "first fruits" was understood to be shortly followed by the rest of the harvest (i.e. the rest of the general resurrection) I'm not sure that we can positively affirm that Paul's description of Jesus' resurrection as the first fruits was an expansion of the normative understanding of "resurrection" in Second Temple Judaism. This is because, given the normative definition, the resurrection of one man would almost certainly give rise to the belief that the end had begun. Paul's metaphor of "first fruits" still conveys this belief.
But you are surely right that the concept of "first fruits" contains a temporal connotation. If Paul were somehow able to know that the general resurrection would not occur for some millenia he probably would have been uncomfortable with the phrase and most likely would not have utilized it to describe Jesus' resurrection.
4) The term resurrection has several connotations for 2nd Temple Judaism. I tend to agree with you and others who say one connotation was something happening to the actual bodies of individuals. How much was the temporal aspect connected and a part of the concept of the general resurrection for 2nd Temple Judaism (i.e. that the resurrection would occur at The End, or right before God’s rule, etc.)?
That the resurrection would occur at the end of the (their?) present age permeates the literature. It is of course found in the book of Daniel, but it permeates the apocraphal, pseudepigraphical, Qumranic, and Rabbinic literature. Nowhere is there found the notion that resurrection will be divided into two chronological phases, with the resurrection of one (or many) first and then the rest at a later point. This is certainly a Christian innovation that eventually arose in light of the fact that the general resurrection of the dead was not immediately subsequent to Jesus' own resurrection from the dead.