I have no experience with 5x druid, but have a lvl66 druid waiting on my main account till my lvl47 druids catch up.
So far i've boosted 'm with my warrior till they were around lvl 40 where my pally was waiting and instanced through ZF mostly.
(also non-raf non-pussymode hardcore leveling \o/)

I've tanked with the pally most of the time, but tried a few things on the run.
druids nuking and pally (offspec)healing seemed to work just as well for trash,
bosses hit them quite hard so i never really tried it,
their gear is kinda awfull atm, mainly wearing cloth and such.

I'm still pondering whether I should make them all boomkin or not,
the 3x reju is a nice heal-tool and when combining it with regrowth my pally never seemed to get lower then 95%.

In an instance you'll need at least a few heals,
and constantly swapping in and out of boomkin is going to drain your mana to much I guess.
(also loosing time which can be deadly to a non-trinity group where succes is all about dps)
I'ld say either make only 1 boomkin for the aura and make the others dps/heal combi or have one dedicated healer.