LR Mobile N00b Questions

[#1]

I attended a great LR primer at Adobe MAX, wonderfully presented by Ben Warde and would like to start using it for the very least the Cloud storage aspect. I have always kept my photos (actually all my data) on external drives, copying over the new ones every two years. What is confusing (and was confusing about LR Classic), is how LR organizes/stores photos. When trying to import my 8k+/34GB+ photos, it warns me about not enough space on my C drive. I don't want the photos stored there. 

So does LR create copies of your imported photos? If so, why?

Of equal importance, if I am using a work-owned account for my Cloud storage, if I ever switch employers, how do I keep my Cloud photos?

[#2]

Ben seems a bit of a comedian, was it entertaining?

Anyways, first questions.....

By Mobile I guess you mean the whole Cloud Ecosystem? (Desktop, Mobile, Web, Apple TV)

Do you intend to store all your photos in the Cloud going forward?

Are the photos you have on the external already in a Lightroom Classic Catalog? (with edits etc.)

To try to answer your questions.....

Lightroom (Cloud) Desktop makes a local copy of the photos before it uploads to the cloud but these are cleared after a time depending on cache settings in the Preferences and other factors (like if you edit them).

Photos can be transferred from one cloud account to another without downloading them.