Hey, I didn't try yet your engine but if the screenshot is from your engine the view is not really an isometric one. I am doing an IsoEngine if you are interested in you should have a look:
https://sourceforge.net/projects/isoengineas3
I also have an IsoEditor that you can test online here http://angelstreetv2.free.fr/as3/IsoEditor/
https://sourceforge.net/projects/isoengineas3
I also have an IsoEditor that you can test online here http://angelstreetv2.free.fr/as3/IsoEditor/