Hmm, Re: Days above ground. Have any of you reset the game? That resets the clock. We will look into that one.
@ god: Regarding the arrows, we will take a look at arrow recovery, thats a good one. Re: feeling constrained, vehicles are coming soon, they will increase your search radius.
Re: NPCs - NPCs are hard to find, and almost impossible for lower level players. This is by design, you are not "lucky"
Re: Leveling up - We had leveling up info on the original UI, (XP needed for next level), but it got scratched in favor of a tidier layout.
Re: Leveling weapons - Weapon level ups are an advanced feature that's coming, will be included in "crafting" update
Re: Achievement, take a look at the achievements table if you haven't (Player status>touch achievements)