That works.

tbf, If you want to introduce a mechanics system, I'd still be fine with that too, but you should have some pretty clear rules about how everything works, or just steal from an existing system (like D&D, Fate, Numenera, etc). The wisdom on this site (and plenty of other sites) has generally been run either a fully free-form game [i]OR[/i] use/create some game mechanics. Mixing the two haphazardly is a recipe for headaches.

Some ideas from other games I've been in:
- If PvP happens, the winner(s) should be pre-planned
- Use stats for tie-breakers to solve dispute in combat or competitions, otherwise leave it to the imagination of players
- Provide a brief description of what each stat normally does in the context of the game/story (like, increasing X stat give Y benefit)
- Stat-less damage categories, like "weak damage", "moderate damage", "severe damage"

If you see a good idea from here or elsewhere that would help, just steal it. No shame~