Is there a way of adding Subtitles directly in the VSE? Or do I have to make an animation of text meshes and add it to the video via a Scene strip?
Since Blender 2.76 (or more detailled, since the Gooseberry Branch) there is a great new Text Effect Strip feature which will do the job for you! Mikeycal Meyers already made a great Tutorial on this topic.
Edited: There is now a built in VSE text subtitle tool. But it has limited functionality for adding text to a screen. Edited: Apparently now you can word wrap the contents of your text entry string. But you still can't change the font or direction of the drop shadow.
To make more elaborate supers (superimposed text), you must create a another scene and add it's scene strip to the VSE edit scene. However this is inefficient, I would recommend rendering and text to image files first.