Iranian bomb plot bogus?

I was just talking to several colleagues and it turns out they share my scepticism over the Iran bomb plot---the allegation that Iranian intelligence operatives sought the assassination of the Saudi ambassador to the US via the help of an Iranian ex-pat cousin of one of them who also had contacts with a Mexican drug gang who would be the contractor for the assassination. Here are a few details that stand out to me:

In the released justice department material, we learn of money transfers into an account allegedly controlled by the drug gang but actually controlled by the US, since the drug gang contact was actually a DEA informant. But there is no information about the bank account used to send the money. Why is this omitted from the material? Where is the sending bank located?

The evidence includes transcripts of phone calls between the defendant now in custody, Iranian-American Manssor Arbabsiar, 56, and Gholam Shakuri, said by Arbabasiar, in a vague kind of way,  to be part of the Iran's intelligence agency, which the US identifies as the Quds Force, the covert, operational arm of Iran's Revolutionary Guards. But it does not include information about the phone number used by Shakuri to speak to Arbabsiar. Was it an Iranian government phone number? Or just a private phone number? 

Since his arrest, the details of the plot have all been provided by Arbabsiar, and he cooperated with the government in making these phone calls, which were recorded. But Arbabsiar might not be the most reliable of narrators. An American citizen who has lived in Texas since he arrived there to attend a university there, he has run a used car lot, he has been arrested four times in Texas from 1993-2001, and his recent source of income seems a little obscure.

Reuters has a story up expressing the doubts of some expert observers:

Yet questions abound over the putative plot, not least the classic ones of motive and means. Many analysts are skeptical.
What could Iran hope to gain from an assassination that would have brought fierce retribution? Why try to recruit a hitman from a Mexican drug cartel instead of using its own?
On the other hand, why would the United States, even with a presidential election looming next year, go public with such accusations unless they were well founded, knowing the impact they could have on an already volatile Middle East?
"Killing the Saudi envoy in America has no benefit for Iran," said independent Iranian analyst Saeed Leylaz. "Why should Iran create hostility when the region is boiling?
Dismissing the "very amateur scenario" as out of character, he said: "Iran might have conducted some political adventurism like denying the Holocaust, but an assassination attempt, particularly in America, is so un-Iranian."

 ..................................

"The United States would not blame the IRGC (Iranian Revolutionary Guard Corps) without substantial evidence," argued U.S.-based global intelligence company Stratfor.
"However, this plot seems far-fetched considering the Iranian intelligence services' usual methods of operation and the fact that its ramifications would involved substantial political risk," it added.
Former CIA agent Robert Baer poured scorn on the reported Iranian conspiracy. "This stinks to holy hell," he told Britain's Guardian newspaper. "The Quds Force are very good. They don't sit down with people they don't know and make a plot. They use proxies and they are professional about it."

 One of my colleagues told me that when he first heard the story on the radio, he thought that the allegations, the news coverage, and the very story he was listening to was part of a larger plot, to move toward a war with Iran. He has no background in persian gulf/ middle eastern politics, but is also not conspiracy minded. Another of my colleagues, who does have strong expertise in the middle east, believes that the allegations are far fetched, the coverage extreme, and all on track to lead to a war with Iran. He advised me to monitor what the Israeli government does.