Q.bottle brush removal of dead flowers
Someone told me to remove the dead flowers by twisting them off and then you don’t need to cut or prune if shape is ok. Is this ok to do?

You can cut off the spent flower, that's okay. But pruning the bottle brush is a bit more complicated than that. Here are a couple of articles that tell you more: https://www.gardeningknowhow.com/ornamental/shrubs/bottlebrush/pruning-bottlebrush-plants.htm
http://homeguides.sfgate.com/trim-bottle-brush-tree-48764.html