Undungeon-fantasyfing your DF game

[Varyon]

I would say start by defining how powerful the characters are meant to be starting out, probably following the Delvers to Grow guidelines of Novice [62], Journeyman [125], and Master [187], with Veteran [250] as a further option, and build them as delvers (IIRC these also match the point levels available for Henchmen in DF15, the templates for which could be used instead of, or in addition to, DtG). Then give them another pool of points - or perhaps a choice of several lenses - to represent them being people in a non-DF setting, with professional skills, social skills/Advantages/Disadvantages, etc. This will still lend itself to violent heroic fantasy (delvers are fairly combat-optimized), but now the characters can have more meaningful interactions with the world itself. This will maximize the number of DF resources you can bring to bear while still allowing you to run a campaign that isn't about killing monsters and taking their stuff.