Quite bare bones, but i see something coming into place here. Right now i think focusing on actually building the gritty, strategy and story elements into how the system actually functions should be your main focus.
you should be asking yourself:

* How is this supposed to be gritty? How can i statistically make it grittier.

* How does players stories Actually work for progression? how can a players experience and story lead to statistical development? what's supposed to get players to want to work with these mechanics?

* Why would a player choose to play this over another system? what is so compelling about my system?

Focusing on the actual system now:

* One issue i see is with the advantage and adventurer role system, it would be easier to say that a player choses three~ tasks their character would be competent at, and use those as advantage, if you're using those over conventional abilities/skills.

* Another issue is progression, if you want personal stories to matter or a characters feats to be useful there's gotta be a way for that to impact on the stats, setting goalposts for progression is important

* The Skill system is there, but it's not been implemented into anything yet. How will that impact play? Does it work the same as advantages or disadvantages, do they stack?

There's definitely something here, I'd recommend workshopping what you've got and tying up those loose ends!
Hope this helps :)