Achak supposes that Mr. Abbey could be the one providing the vampires with fine works of art to act as bait. This would suppose that Duncan, being an immortal elf, was playing the long game by casting in his lot with his fellow immortals (the vampires), but Achak probably isn't that paranoid yet. He's asked for Duncan's help in making arrangements for and in Manhattan, which suggests a reasonable level of comfort with Duncan's trustworthiness.
Achak is probably not going to immediately pawn all of Stake's stuff, but he's not above poaching supplies.
As for Manhattan plans, I think we were waiting on some commlink hacking to help inform those. I had forgotten that we had the Johnson's commcode. Again, some commlink hacking would help inform our strategy. (Do we wish to impersonate the runner team, and report on their success? Breaking Iki's comm will help determine if that's feasible or if some other approach is more prudent.)