I am at lvl 66 now and although Ive ran the Azeroth instance content multiple times I decided to do it again with my MB team. This was to get instance practice early as possible. What I have been doing is running instances a little ahead of their level. So I ran Ramparts at 62 - BF at 64 and now Ive just cleared Steam vaults at 65. I have found this the best way to learn. Im also gearing up from those instances to the next one. Theres plenty of time at 70 to run and gear up in the instances before you go all heroic.

I use a pally with my 4 shamans though and she is very hard to kill especially with a resto shaman in the group. She soaks up the damage so my shamans get left alone. If your shamans are dying one sugestion i would make is to make sure you havent put in any leather or cloth on your team or given in and put on a staff or other 2 hander. Shields for me on a 5 shammy set up like yours would be essential. get the best you can.