It's possible, just have to find someone who will do the coding.

For Presence-Social Networks, it is best to do the "ping" (it's not really a ping) by automatically posting, for example: "New post on my blog! Visit {some tinyurl here}".

The plugin will have to auto-generate tinyurls as well, but I'm not sure if tinyurl offers an API.

For #2, I think that is best asked on twitter and/or twirl ;)