I'm using Stroll with Stream.
Indeed autocomplete is currently not working.
Backlinks appear like David said. They're just transclusions, so they are not editable. Also, only the node is shown (ie., not in context).
I agree it would be extremely powerful to have the features mentioned by vrpape.
One thing I miss in TW core is an alternative way of transcluding a tiddler which shows it as a live editable tiddler, like Stream does for example. But even in Stream there's a limitation to this. For example, if I want a certain node to appear as editable in multiple tiddlers, I need to manually edit the stream field within a tiddler. It does work though, so perhaps it's a possible enhancement for that plugin.