Others may disagree but I don't find the layout of things in the relationship editor intuitive.
When I see it, my eyes work from the top down: current entity (fixed); Type [of relationship] (editable) - and that's what I drop down even though it's probably relating to the wrong type of entity (the third thing I see). It works fine if I've got an MBID to paste but otherwise I'm often looking for a relationship type that doesn't exist
Would it work to simply move the Entity 2 Type drop-down up a row to where it currently says "Type" (which I'm not sure is very useful). That might be confusing as well... Any ideas?