If were really offering opinions, the wallpaper (as a woman these are the things im going to notice) has to go in the master bedroom/bathroom.
I have no issues with the stuff on the walls. They aren't too cluttered.
The basement however, could use some fixing. clean it up/store stuff in new garage
Also, the kids bedrooms are VERY overwhelming colors (while for hte kids they are great, but as a buyer, its too much) All i would think about is all the painting i would need to do, and the wall paper removal i would have to do.
The kitchen looks fine to me.
The Hallway/entrance way has an artwork hanger in the picture. Either take it down, or fill it up
the crosses i would take down, but thats it.
I also have a love hate relationship with the pumpkin/pink that is on the walls of the pellet/wood stove. My inlaws did that same color to their room with similar style stove setup and i dont get the correlation to it and the stove, but- Neutral colors will always be a plus.
Look at he simplicity of the colors in your kitchen and go with that.