The link title issue is quite complex and requires to understand the purpose of the plugin, which is to allow you to insert mutating links to data in your posts.
For instance, if you write a post about [C# programming->] today and have no data on it on your web site, then the link will fadder and be invisible. But as soon as you add a C# programming link to your bookmarks, all the references to C# programming will suddenly link to that. And when you eventually write posts on the topic, the links will all mutate and point to the latest relevant post.
Moreover, a future version of the plugin will feature link autodiscovery: This means it will identify the post's key topics, and contextually insert links in the text based on feedback from user interactions.
Thus, it is very much impossible to determine what the data will be pointing to. So letting users hard code a link title is nonsense. Remains automatically inserting a title, which I've in mind in a future version. Namely, this would be the resource's excerpt, link description, category description... at best with whatever is present.
Regarding external links, the plugin doesn't add much value at the moment, but I've plans to enable distributed autolinking as soon as I find some time. Distributed smart linking could be achieved via XML-RPC, or via the API modules of search engines. In essence, the distributed link would let you write about a [book at amazon -> GÃ¶del, Escher, Bach @ amazon], and get a link to precisely that.