I don't think you can attach various tiles created using the 2D Toolkit. The more I use 2D Toolkit the more difficult it seems to be for my particular game. Every solution I run into is to just use built in Unity functions. I got 2D toolkit for it's tileset abilities, but it's proving to be more troublesome than it is worth.
The objects that I need to add special events too are tall grass, cave tiles, trees, water, ect. I got the toolkit so I wouldn't have to copy and paste large sections of prefabs to make my world. It is seeming as though that is what I'm going to have to do regardless