Ah, the fun of semantics! It's amazing what a difference it can make, though, when trying to convey messages to a non-SEO or Web group.
I traditionally use "on site" and "on page" SEO for the "internal" items you have. That's partly driven by the fact we have some people working on internal search on our site so people get confused with those projects if I use the term "internal."
I do use the term "external" or "site SEO" for the projects you list as "external." I try to differentiate what' specific to a page and what's specific to the overall site to help people understand there's different layers. And to help educate that because you optimize one page doesn't mean you've done SEO
I also like to educate on "technical" SEO so my team understands it's not just about keywords, but site performance and other things that can mean developer and IT resources. I learned fast that there was a perception that if you just put the keywords in the right place, revenue would come.
As for more social related information, I use buckets for social sharing but also make sure I hammer home the need for "in bound" marketing. There's a difference between those as you need the content to drive in bound but you use social to help give it visibility. And I think it's a more comprehensive element of marketing.
I would argue though that visibility isn't segregated by how you mentioned in. The technical build as well as the keywords selected can both play into visibility. You may not have any 500/404 problems, but if you picked keywords only a small audience cares about, you also limit your visibility.
For me, part of my terminology is dictated by our own internal jargon and how to map back to it so more people "get" it...while I talk about complicated things out of their wheelhouse that can end up confusing them anyway!