Taterbug,
I know this post is a few days old but wanted to say I think both are great ideas and figured if more people showed more interest, it may up the likelihood of getting these features added.
I especially like tagging people - there have been many times where I know a certain member would have better knowledge/care advice and rather than just mentioning the individual or PMing them, tagging them to get their attention would be beneficial.
I believe if videos are uploaded on photobucket, they provide a link to embed the video, however photobucket is by no means a popular uploader anymore, especially for videos. I think the option to embed videos from other sources would be great.