Heart Rate Sensor and Blue tooth pairing

Overall pleased with the watch, however the heart rate monitor doesn't work, Ive tried all the videos and am reluctant to do the Hard restart?

Normally it works without any problems, and you do not need to do anything else than putting it on your wrist. Once I even tried it over a sleeve, and it continued to work anyway, so I've put a piece of completely opaque thick leather, and it still continued to work, I used a thin metalized foil and it still worked, so if it does not work in your case, I guess you have to be clinically dead since some time. Did you consult already your physician? 

Joking aside, try another wrist, the inner side of the wirst, or try attaching it to the ankle. You could have a medical issue (i.e. strong periferal vasoconstriction, or an unusual level of hemoglobin), or your device might be simply defectuous. Go back to the retailer (unless you bough it online), and try it with another unit. Also check out the document The Heart Rate Sensor on My Watch Is Not Accurate for some other tips.

What i eventually found was the watch needed to be plugged ito a power source each time for pairing.

No, it does not. If set up normally, all permissions enabled, battery optimizing on the phone for the app disabled, it syncs anytime automatically without needing to be on the charger. Have a look at the Sync / Connection Troubleshooting Guide for some hints.