For the falls, it completely depends on how much work the "guide" does for you or your group. If you are capable of going up without much help, then you may not need to tip at all. But when we went, my mother in law was with us and she required a lot of help. We ended up getting assisted by a completely different guide because ours was way ahead of us. I ended up giving a good tip to the one that helped us. After all, a tip is a reward for good service. I rewarded the correct guy.
As for bags, a 1 or 2 a bag is fine. It really depends on the number and size of the bags. You cna be the judge there. But I always think that I need to tip well as "insurance" that my bags get on the ship....
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise, Magic 1/14
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013