Well, it's a lab, so the entire point is to have the software on all the machines so students can follow along.
As for imaging, I have found in 20 years of installing software that imaging is a crap shoot at the best of times, and silent installs are a much better option. Especially since that is exactly the problem silent installs where designed to solve, mass install of software. And in this case it isn't even the ideal circumstances where imaging might work, rather the hardware vendor could provide multiple different machine configurations in a given lab, at which point imaging is a big ol bag of pain.
No, the need to do silent installs is real, and the only alternative if that can't be made to work is to use different software. Since Office is not the focus of the classes we can get away with file format compatibility. Indeed, I suspect Adobe Acrobat is also not going to be installed, as there are other easier/better alternatives.
That said, I have been digging around, and it sounds like I can use a blank key to get a demo install. And there seems to be a tool to make click & run work, which is good since MS decided to abandon the perfectly functional MSI based installer for the most part. But, if anyone actually has experience with this I would love to hear of any issues or pitfalls.
Thanks!