I have very little hope in the AI of the mobs imrproving to the point that it will ever give some top-tier casters a challenge. In pen and paper dnd, the DM can tailor the dungeon so that the casters will never feel too op because the DM can change circumstances, monster abilities, monster items and spells on the fly. The DDO environment cannot currently do that to us. Given the limitations of the hardware and software we are playing against, casters will always be able to create builds to run through content like hot knives through butter, because the environment will always be predictable. Even if the developers wanted to create dynamic situations that would be more challenging, their only tool seems to be the HP increase hammer. Nerfing R8+ caster damage seems to be a way to combat that so that casters have a bit more challenge. Right now, the state of inquisitive burst damage and some melee damage, maybe un-nerfing caster r8+ damage might not make a difference idk, I am not sure I care too much, maybe worth a shot?
But buffing melee self-heal? I don't have a ton of playing time, but I think I ran about 14 raids this past week. I think maybe half of them had no healer. We had no cleric, fvs, or bard shouting at the party. These were all pugs and all successful. The raid selection makes a huge difference, and I didn't track, but I do know we ran R1 Baba, r1 PN, H THTH, h Dryad, n Hunt (lag), and h VOD without healers. I know that clerics and favored souls do not need to limit themselves to healbots, but why bring a healer to any of these raids if melee self-heals are buffed?