In regards to Lei Shi, I cannot make too many comments. As far, however, as Tsulong is concerned, I think that she can be doing more single target throughput by switching two talents.
The AoE healing is not quite so important as the single target for day phases, so the two talents I would use are Echo of the Elements (where I know she was using Elemental Mastery) and Unleashed Fury (where I did not see any castings of Unleash Weapon in her buffs uptime, though perhaps it does not display there).
Also, yes, mastery is a far more beneficial stat in this tier of content than haste is, simply due to the fact that the mechanics of most of the encounters will leave players in low health situations enough to where mastery will give more overall benefit than a slightly faster casting time will.
I won't claim to be an expert on shamans, but from the perspective of a fellow healer, that is what I would change.
P.S. : For anyone who looks at this Wol report, yes. I am also speaking as someone who was in this very same raid.