I’m very sorry to hear that you had this experience with your Librem 14. If you send me a private message including your order number, I will investigate how we can rectify the situation with your missing Librem Key, why/how the support department failed to assist you, and how Purism can re-earn your trust as a valued customer.
Support has reached out to you describing the option to skip boot verification and ignore tamper detection, so you should be able to boot and use the computer in lieu of a Librem Key replacement. In addition, please check out PureBoot Getting Started Guide - Purism - Librem products documentation for more information about PureBoot and how to reset/configure your system. If you still have questions, please feel free to ask here or (ideally) place an issue directly on the repository here so that the guide can be clarified and improved for everyone.
Pureboot Basic appears to be the default in the Purism Shop. This makes sense because the Librem Key costs money and so you have to add it your order and without the Librem Key the customer should at least get a result that works. However …
I would like to say that only Pureboot + Librem Key is actually secure (always subject to what your threat model is). So I really would like to see some Product Manager attention on making it easier for newbs to have a secure computer. @JCS ?
It would appear that ordering with Coreboot is not offered in the shop.
As you say, documentation starts at the time of sale i.e. make sure that the customer understands the options that are available to buy.