You don't have to track minor injuries after your 3rd, they just slow you down after that.
Some folks have a struggling experience fighting the randomness of the dice. It sounds like you've got it solved ok. I think miru is less a game about pure mechanics and one that is more entertaining if you engage with the story. After day 25, you can end the game sooner if you think you're invincible and take on the god.
In miru 2, i added more mechanics for folks like you who find more entertainment from the mechanics. There's poisoning, weather, and enemies occur more often. (along with more god fights)