if RRR is any indication, then DD2 will have party-based adventures as well. this means healer can hire/summon party members 2 bolster his offense as well as defense.
with that, single-player for healer is possible with party. but then what if players want 2 play this character on his/her own, i.e. without party support? that still bugs me.
quests solved in unique ways is possible depending on the nature of the quest. as i mentioned earlier the healer is totally goodie, he may not get any quest that involves killing(unless it's baddies), stealing, lying, etc.. . maybe the healer gets unique quests that only a healer can solve.
this can go 2 more extreme level, which is a single-player campaign unique to the healer only. of course some/most people may not like that as it takes away some elements of RPG which are choosing class, skills(other than healer only skills), & alignment(healer is goodie). so freedom is a bit constricted but this is 2 make the story/adventure tight & 8 the same time fluid.
take about story for the healer, i have 2 do some more brainstorming. hopefully i have something out within 2-3 days.