I think gaining the favor of Ethexae or Yakau without ever completing their personal quest might be worthy of an achievement! Or perhaps just Ethexae, depending on how you're balancing the difficulty. I managed to auto-recruit Yakau once without even planning for it, but Ethexae starts with approval so low that I think you'd have to plan for that to happen.
Managing to complete Chapadoc's quest through alternative means might be worth an achievement as well. And maybe znantvat gb trg Mbybg gb ibgr sbe lbh, ohg gura univat vg gnxra njnl jura Rfznenv ragref gur enpr?