interact with target + 5 team

[zenga]

should I use other software as well, other then isboxer and jamba ?

Nope, a key broadcaster + the addon to make things easier ingame is all you need. There is no really other software besides that, except software that comes with your keyboard/mouse to remap a button.

Like if i send my tank in then all my other toons would instantly follow and be on the tanks backside, thats not a good thing... so what do I do there ?

When you run in with the tank, you can hit the 'back' key of your shamans, that will break follow and they stay away and in position. After doing that 5 times you'll know where and when to break follow

And if I am using a none shammy healer, then how will that heal the tank and my shammys if it needs to ?

You can heal with keybinds, i.e. 5 macro's that send a heal to a teammember. That's the way I do it. Other players use repeater regions (i.e. mousebroadcasting), where they heal on the main toon with grid/vuhdo/healbot and clique and the mouse coordinates gets send to the window of the healer as well, i.e. the way a party healer would heal. I'm not much of a healer and I find keybind heals way more effective. /target toon1 /cast lesser healingwave, and this bound to key 1, key 2 has the same for toon 2, etc ... I also use a modifier, so depending if i use that key + shift or alt it can cleanse, cast riptide or a big heal.

am I flicking constantly between pip windows or needing too when tanking, dpsing, healing arrgg ??

If you stay alive you should never switch between windows. It's good if you want to 'do stuff' on a slave, like crafting, setting talents, etc ... or when your main toon is dead in pvp/pve, or when you have to do a certain quest solo on a slave.

I dont understand how you can taunt, hold agro then somehow dps and heal all at once.

That is the skill that is needed to multibox: i.e. multitasking.