a few admittedly ill-informed thoughts on this:

I keep hearing about possible re-engined 767s but also hear elsewhere that there's really nothing out there in the thrust/weight class to do the job properly. If that's the case it's hard to imagine RR or anyone making a low production volume engine for this purpose alone - unless it could also work for a future 797.

On us ditching the 350s... we just bumped our order from (I think) 30 to 40. We seem to be going in the wrong direction if that's the plan.

As far as the 330 vs 787, my guess is the right screaming deal would lean us towards the 330, since we're already planning 350s and there's no full sim course needed to switch between from what I understand. That being said, if the Iran deal is off then maybe Boeing is also looking for new customers for 787s.