John,
Newbie questions, but just couldn't figure it out
It appears that every new ingest creates a file based on a date stamp in PM folder (20181115)
That depends on your settings. By default Ingest will create a dated folder for you, but you can turn this off. See the following documentation for information on Ingest:
http://wiki.camerabits.com/en/index.php/User_Manual_Flat_View#Ingest1) Does PM actually move a snap from its download folder (say in a DCIM folder) to this new folder or does the new folder contain a virtural copy of the original?
Ingest doesn't delete the images on your card by default. It copies the images to your destination folder. You can set Ingest to delete the files on the card after a successful ingest if you want it to.
2) Can a keyword search span across PM folders? This is really the reason I bought PM, was the hope that after applying keywords for folders via stationary, I could do a global search across all files.
No, but you can open multiple folders into a single contact sheet and then do a Find. PM6+Catalog will support searching keywords and other metadata across an entire collection of images.
It appears the idea is that I have some "master" stationary file that I more or less customize for each new ingest. The relationship between the file wide stationary file and individual photo captions is also a bit vague.
There are two dialogs. The IPTC Stationery Pad dialog is for applying metadata in bulk to a selection of images or during operations such as Copy/Move, Save As, Ingest, Uploading, etc. The IPTC Info dialog (accessed by clicking on the 'i' button that appears over your thumbnails) shows you the metadata currently in your image and allows you to edit it directly.
HTH,
-Kirk