RoR uses different handling for snares. If a target is already under the effect of a snare, any further snare debuffs will be ignored. Existing snaring debuffs cannot be refreshed. Example:
SM applies Quick Incision -> 10s snare
5s later, IB applies Binding Grudge -> target is already snared so the snare debuff does not even apply at all
3s later, SM tries to reapply Quick Incision -> snares cannot be refreshed, Quick Incision remains at 2s
2s later, snare comes off
Regarding ToT: It works just like Shining Blade:
https://www.youtube.com/watch?feature=p ... CACU#t=140
Note that when he uses ToT, he gains the "Damaging" buff himself (you can see it in his WSCT) and it's not applied to the enemy.
Regarding credit: Most group buffs should give credit to the player who triggered them (Flames of Rhuin, Covenant of Vitality, Prayer of Devotion, Frozen Touch, Tooth of Tzeentch, etc). Whether they actually do is another matter.