I don't want to enslave the Fulings; I want to tame Moder. Someone suggested riding drakes, but they're too small.

As for the Fuling, since you've offed their god, I can see at least some of them serving you out of respect for your power. That can have hilarious results, if you remember the quest in the Dragonborn DLC for Skyrim that ended up with you becoming the head of a clan of Riekling, creatures who are very like Fuling (small spear-throwing goblins, though the Fuling, thank goodness, don't ride wild boars).

Interactions like that would be difficult to write but would improve the game. Odin sent you there to assert his supremacy as All-Father, not to kill every single living thing in Valheim.