Not exactly. I personally find link-style posts with external URLs in the feed to be a kind of usability issue… Most feed readers don’t handle them well, so it’s confusing to know where the link is going to go. So I think the best approach for link blogging is to just include the external link as a hyperlink for some word or phrase in the post commentary you’re adding. (If you want a much longer answer, I blogged about link blogging several years ago here.)
No, although if you include a link to a tweet, I think Twitter will usually show that as a quote tweet. But there’s no support in Micro.blog for native retweets.