WebPlus X5: To embed or link?

I'm pretty computer-literate but have a simple issue.

I have a small site, but WPX5 often spends time 'Not Responding' - particularly when uploading.

After a little research I have decided to link, rather embed movies and photos, rather than embed them.

I'm not worried about file size, but wonder ...

• Presumably, if I link, my first upload will take longer, but subsequent ones will be faster?
• The relevant files will be stored on the target website 'somewhere'
• Changes to pages which reference the pics/movies will simply upload the changed link?
• I can somehow show the same pic on multiple pages, but only store it once on the site?
• How do I do this?

Or, easier, is there a DETAILED document on all this, somewhere?

Thank you