In my experience, the conflict star can be cured by the color red or by regular burning a candle. If the fruits on your pictures are red, then it's no problem. Just make sure that there are no blue, black or green colors. I have had the experience that wooden objects such as tables do not work as wood element because the wood is dead, their effect is more like earth element. You should be fine with a bowl of cherries.
Regarding your second question: it depends. If you feel the effects of the conflict star try the hexagram in your relationship direction. If you can place any red object close to the office door it will work as well.
All the best,