im not running a mixed group, but just to add my 2c.


im running 5 shamans, using the /focus system to assign targets.

first off on my nr. 2 key i have:
#showtooltip
/cast [target=focustarget, help]lesser healing wave(rank 5); [target=focustarget] Lightning bolt

and on my nr.3 key:
#showtooltip
/cast [target=focustarget,help]Chain Heal(rank 3); [target=focustarget] Chain Lightning

(i got a seperated bigbang macro using trinkets and EM + CL)

what this allows me too, is first and foremost to target dmg spells.. but second of all, using my main (having focus) to cast healsx5 on partymembers AND nonpartymembers.

In addition to this, due to lag with getting a targettarget, i also use my F1-F5 key's for direct heals
F1 key: /cast [target='name1']Lesserhealingwave rank highest -2
F2 key: /cast [target='name2']Lesserhealingwave rank highest -2
etcetc

this allows me to INSTA heal x5 on one of my own, especially needed in pvp or pve when 1 target is getting hammered (side effect, agro gets switched too )
reason for using highest rank-2 is cause at that rank total healing done x5 = equal to max healthpool.. would be a waste to use a higher rank.

edit: pressed submit too early
what i also done was using Grid to show party healthbars horizontally, and aligned those above my F1-F5 key's on the screen (check my profile for other posts of mine to check screenshots of my UI). this way i can easily spot which character is in need of heals and mash the right button..

problem though if i switch screen/focusmaster grid shows the back lineup (new master becomes Party1 on his own screen :S), but you get used to it and mentally adept. at least i do