I've used the Avent bottles with the ring and the only leaking issue I've had is once when DP assembled it and put the ring blue side up instead of down... Never noticed any issues regarding needing to tighten it a particular amount or way.
And as far as the teat collapsing - I've only known it to happen when the sucking strength was too strong for how much could come out - ie. slow teat... So maybe try the next faster flow??