Re: chain rubbing chainstay
If you're a welder then consider something like this.
As for quiet; this rig is noiseless and this particular one has over a thousand miles on it without a problem.
I'll agree that the kit supplied tensioner leaves something to be desired but don't discount what can be done with a little ingenuity as far as a chain tensioner is concerned.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"