Ok.. what I think:
-the crown molding suppose to go all the way up to the ceiling, without the shadow gap
-the wood is too orange
-the wood texture mapping / texture on the bottom cabinets is not looking good- the repeating dark vertical texture patterns/ fragments
-not sure why some of the elements/ objects are that bright (books, the figurine in the middle, sofa)- looking like pasted in photoshop.. not real
-sun falling thru windows also not too realistic- no 'real looking' shadow of the framing
-generally speaking- no 'real' illumination, seems like you put some artifical light source in the middle of the room with shadows turned off (cabinets are not casting shadows, sofa the same, books too bright without any reason- something 'smells fishy' there
-in the interior like that I would put some ceiling lamps to light the book shelves
-the exterior background image is just a bit too dark.. not much, maybe 25% brigher would do the job
not sure why the render looks artifical/ fake so much- please be honest- did you use any filling light without casting shadows?
the model is good- I think it would look much nicer when you use just the vray dome and some hdr map for illumination and add the book shelves ceiling lights
I've done a quick project similar to yours some day - not a great one but it illustrates the points I've made in the comments