Crunching chainline noise

I wouldnt change chains every few months just to make your drivechain last longer. run a drivechain til the chain snaps or theres no teeth left, then replace the lot.

Constructive criticism: Chainrings last longer than cogs which last longer than chains. Riding them all to failure is (I guess) an option if you're confused or disinterested. It's a waste and as advice... it's bollocks.

If you replace your chain when it's at 75percent-dead, cogs every few chains and chainrings every blue moon you'll save cash and avoid snapping chains.