Lightroom has a whole panel dedicated to renaming, described in detail on pages 47 and 48 in Martin Evening's book. Then the next 4 pages contain important information about how to import the photos so that they store and are defined in metadata the way you want them. But you should give it a test run to see whether it meets your requirements.
I don't see anything particularly "wrong" with what you propose to do, but once you are making this kind of transition, it may perhaps be an opportunity to simplify your workflow and storage arrangements. An early decision is whether you need both XMP sidecars and DNG copies. I don't do DNG, but many people consider it important. Immediately after an Import, the first cull I do is to delete real garbage that I know I'll never need again. It's better to do this before creating Collections, because when you work from the imported photos before putting them in Collections, you can directly "Delete from Disk". If you work from a Collection, you can directly delete from the Collection, but not from the disk. Once I've put everything I didn't delete from disk into a Collection, the next decision is how to distinguish the wheat from the chaff. I use Lightroom's star rating and labeling functions for this, so nothing needs to be saved or stored in more than one place - the original storage location. For example, I'll use one star to denote an image selected for further attention, then yellow label it once it's edited and green label it once it's printed. They can be easily sorted and displayed according to these criteria so I always know where I stand on the processing of a photo shoot.
Once edited, the next issue is how to print them. Given the quality and capability of the toolset in LR's latest release, there's almost nothing I need to do in Photoshop; in fact I make it a point of stretching LR to the limit before further processing the photo in Photoshop. So about 98% of everything I do never leaves LR. The Print Module in LR is excellent and well integrated with the develop module. For example, when I put something up to Print and examine the photo before clicking print and see a tweak or two I'd like to perform, I go back to Develop, make the change, and it is automatically reflected in the Print Module (this does not apply to cropping, where it is better to remove the photo from the Print Module and remount it after making one of these changes). What I'm left with is nothing more than the raw file and it's list of edits, all kept in the same storage location.
For those photos that do need some treatment in Photoshop, LR has a function allowing you to open the image in PS for further processing, which happens at whatever stage of LR processing you choose, then once finished in Photoshop you save the photo as a TIFF of PSD, and it automatically opens as such as a separate entity in LR, allowing you to continue doing whatever else you want to do with it in LR.
The security function is confined strictly to how I back up my files in general. For the LR catalog, every time I quit LR, I back it up to a separate drive within my computer, but you can back-up the catalog to an external also. Before I shut down my computer for the night, I use Carbon Copy Cloner to back up the whole system drive to an external (this for Mac, but Windows has Acronis or similar for the same functions); I have my Pictures folder on this drive, hence ALL the LR stuff is automatically backed-up in this procedure.
In sum, all this is configured to minimize storage requirements, minimize duplication, maximize processing efficiency, and having to remember and manage as little as possible.
