I will be removing a wall to open up the kithen and sunken living room to make into 1 large room 22X22 approx. the wall which will be removed has a double cold air return vent, I will be moving the vent across the room when raising the floor in the living room to match the floor height in the kithen. my question is can I have the new vent location near the same wall that the hot air vents are located? and is there a required distants between them that I will need to achieve.

You do not want your return air located close to the supply. You can run into a recirculate problem when the supply air is not dispersed into the room because the return is pulling it directly back to the source.