2. Chi, Ki, and Qi all are defined as The Vital life energy that is thought to be inherent in all things. These three are all the same thing thing just different words.
Chakra is defined to be the seven points of Spiritual Power/Energy located along the body. Rei is Spirit Energy so it may be closer to Chakra than Chi/Ki/Qi.
Rei and Nen have no actual Definition on Dictionary.com.
