Demystifying Workflow, Blueprint, Publish and Actions You Can do With Such Items

I was playing around a while ago with some Components in Workflow, in Blueprinted situation, when I noticed some strange behaviour.

I was trying to place a v0.x Component (in Workflow) on a Page in a child Publication -- can't do.
I was publishing a Component linking to a Component in Workflow. It works, but it will use the values from the last saved 'link-to' Component -- makes sense. But even when publishing with ActivateBlueprint=true, still the last major version of the 'link-to' Component was used.

This all triggered me to summarize these weird cases, as follows:

• A _new_ Component (version 0.x) in workflow:
• is visible in its own and child Publications (GUI & API);
• can be published in its own and/or child Publication (GUI & API using the “ActivateWorkflow” flag). Publishing follows most of the rules we know (DCPs get published, Page republished if published previously), but some don’t actually work as expected: Components “linking-to” the Component in workflow will see the ‘last checked-in’ version of the Component in workflow;
• can be put on a Page as CP:
• in its own Publication – (GUI & API);
• in child Publication – only API (because minor version new Component is not visible in GUI’s CP selector);
• An _existing_ Component does all the above (it can even be put on a Page in a child Publication both in GUI and API)

Note: Be careful with the implications of placing a v0.x of a Component on a Page: you are responsible for cleaning up the Page (remove CP, unpublish Page, delete Page), in case you reject the Component (or if you abort the Workflow Process). If you don't, then Tridion will throw an error that the Component is used and cannot be deleted -- which makes perfect sense...