You have to hold it tight or it will slip out your handOk one question I have & that is when I take up the tension on the exhaust side on the front pot how firm does it need holding while pulling it over the cam sprocket??

The chain should be pulled taught (Have I spelt that right

As for one side wearing more than another. They are separate cylinders and should be treated as such. Things rarely wear at the same rate due to different stresses and strains on various components. The only thing the chains share is the crank!
(:-})