While by no means do I consider myself an expert (I've almost reached level 40, but I am happy with my progress) five boxing shamans, I think I might be able to help you with macro's. First of all, and this is something that I found out before I made my team, is it's very hard to do things if your going by name. I go by Party1-4, this only works though providing you know what each character will be. Blizzard determines party #, but whoever the "youngest" character is on the server. Once you've figured that out you can start to do more with macro's. right now I currently use a macro with

/target party1target

To get everyone focused when I need to, otherwise I use a combination of macro's. This is a lightning bolt macro that works pretty well, because even if my main has no target / dies, it will look down the line for anyone else with a target, or find it's own I'm not sure on the number of characters this macro is, I use an addon called Infinibar that uses Pseudo Buttons and macro's so they can be of (As far as I've seen) infinite length.

Code:
#showtooltip
/cast [mod:alt] Purge; 
[mod:ctrl] Chain Lightning; 
[exists,harm,nodead] Lightning Bolt; 
[target=party1target,exists,harm,nodead] Lightning Bolt; 
[target=party2target,exists,harm,nodead] Lightning Bolt; 
[target=party3target,exists,harm,nodead] Lightning Bolt; 
[target=party4target,exists,harm,nodead] Lightning Bolt
/startattack
I'm not an expert in macro's, but what it's "supposed" to do is cast a lighting bolt on it's current target, untill that target dies. then it will look for a new target by going through each other characters target until it finds one that exists, is bad, and isn't dead. this works really well if my main does die, I can quickly switch to another character and his target's (I will follow from Party1 to 4) will become everyones new targets.

Another type of macro that may help you, is castsequence. At my level I don't have the full range of totems you'll have at 70 obviously, but the concept remains the same (As does the idea of "staggering" totems like Tremor).

Code:
#showtooltip
/castsequence reset=15 Mana Spring Totem, Strength of Earth Totem, Grounding Totem, Searing Totem

#showtooltip
/castsequence reset=15 Tremor Totem, Healing Stream Totem, Grounding Totem, Searing Totem

#showtooltip
/castsequence reset=15 Healing Stream Totem, Tremor Totem, Grounding Totem, Searing Totem

#showtooltip
/castsequence reset=15 Healing Stream Totem, Grounding Totem, Tremor Totem, Searing Totem

#showtooltip
/castsequence reset=15 Healing Stream Totem, Stoneskin Totem, Grounding Totem, Searing Totem
This allows me to use one key to drop a standard set of totems on each character. Breaking down how the macro works is simple, There is a reset based on time, in seconds, reset=15, and each spell that is part of the macro is listed with a space in between. You'll notice tremor totems are staggered, with one dropping in the first 3 totem drops, so I have no more then 1 second of fear when I am feared.

Another macro to try out is something that uses "empty" cast sequences. This one in paticular I use to "run away" from someone.

Code:
#showtooltip Earthbind Totem
/stopcasting 
/castsequence reset=15 Earthbind Totem, , , ,

#showtooltip
/stopcasting 
/castsequence reset=15 ,Earthbind Totem, , ,
Each blank space between the comments, will drop nothing, but move the sequence forward, and each character will cast earthbind at a different time. This allows me to run away, push one key every 3 seconds, and drop earthbinds indefinitly. I also use this for stoneclaw totems, and heals.

Healing is a little bit trickier. As a shaman, once you hit 40 you get chain heal. I have two chain heal macro's, one that has all 3 shamans cast chain heal on the main character. I need to rewrite this to make it cast like other macro's I have so it cast on whoever the main is, that i'm playing, even if the first one on the list is dead (I'll post it when I write it). I also have one that will cast chain heal on my mains "target" using party1target. This is good for PVP especially because it makes it very easy to target a character running around in AV, cast 5 chain heals, and pretty much full heal him and everyone near him.

I think the most important macro to have is Grounding Totem, on each character, as having enough of them can make you almost immune to casters (Combined with earthshock it's quite powerful).

Another idea is to use Keyclones Round Robin for certain tasks, as opposed to cast sequences with spaces. I find the cast sequences to be more reliable though, and having a Reset timer on it is nice, as it allows me to return it to the main casting first, when I want. I do however use a Round robin for an earth shock macro.

Code:
#showtooltip
/stopcasting 
/cast [target=party1target,exists,harm,nodead] Earth Shock;
[target=party2target,exists,harm,nodead] Earth Shock; 
[target=party3target,exists,harm,nodead] Earth Shock; 
[target=party4target,exists,harm,nodead] Earth Shock;
[exists,harm,nodead] Earth Shock
This just simply casts earth shock on the target of the first person on the list that is alive. This isn't 100 percent effective as it doesn't allow you to cast it on a very wide variety of targets, and it also causes, when using a character other then your Intended main to direct fire, that character not to cast on the correct target, unless someone else in the party is targeting it. At the end of it there is a command to cast on your own target, in case no one else had a target. It's not perfect but using the same concept it wouldn't be difficult to design something that works for you.

One thing I would note, is that /stopcasting shouldn't be used in a castsequence macro like the earthbind one, as it will make everyone stop casting even if they aren't supposed to. I would love to figure out a way to make only the person casting something stop, but I'm thinking it would be impossible, short of using just a round robin and making it a normal cast.

As far as keybindings go, I use numbers 1-7 regularly, the letters R, T, F, G, and V, as well as Alt + CTRL modifiers for some of them. I also have a XKeys, Which I use for a lot of keys that I need quickly enough to macro, but not regularly enough to put where I can hit them without moving my hand. I use "F" as my lightning bolt / chain lightning macro, and T as my "assist" macro to set everyone on target.

So far I haven't found alot of things I want to focus target for 'yet' but I have already determined how I'm going to do it. I have 4 individual keys, each with /focus party1target. I target a target with my main, then hit the key for the character I want to focus it. Works fine, beyond that you would call it up again with something like /target focus or /cast [target=focus] Lightning Bolt.

Anyhow, like I said i'm no expert, and it's all still learning for me, but hopefully that will help a bit, and give you an idea of what to look into trying. Good luck =D