1) I think unblocking works only file per file, not sure about this
2) But there are different Filetypes so unblocking all is not possible (this is was i first tried)
3) the directory structure complicates this, because it has to be done in every directory
A PowerShell Skript would be nice. But a Copy & Paste from the manual installation instructions of the right command could be feasible, and solves the 'have to unblock the powershell' problem.