Acoustics experts - a little help please

The room is actually 2 rooms joined. My music room and a dining room with a large opening between them. Essentially no left wall for the left speaker and the right wall is about 8 feet from the right speaker. There is a bany grand piano that helps with defraction of the right speaker. Floor is hardwood but I have a nice thick rug and pad under that. See system photos.  

Room is 30 x 18 x 9 

Certainly no expert, but measuring your RT60, reverberation time for your room will give you a start in which direction to proceed. 

Setting expectations straight, 3D is a foolish concept concept in purist stereo.

A BACCH processor will trick and give some semblance of 3D in a stereo rig.

You will need a multichannel rig with ceiling speakers, back speakers etc and object based audio processors for true 3D.

But, if you turn everything loud enough with the stereo and everything’s smacking the face left and right, it could help you not think about (obsess about) 3D. These type of obsessions tend to occur at low listening levels.

Having said that, hang 6 inch traps (absorption) right above your listening position with an air gap like what @mashif  did.

It will mitigate the impact of standing waves/modal issues heightwise. 

(Floor and ceiling are parallel surfaces)

I have 9 foot ceilings and I sit in a 9 foot equilateral triangle with my speakers. Do I need to treat the ceiling?

Maybe 3D is the wrong word. I'm looking for soundstage depth. Paul McGowan talks about it in one of his YouTube videos. Apparently in his setup you can hear images left, right, center and 5 feet back, 10 feet back, 20 feet back, etc. Appreciate the advice!