I think there should be more handmade weapons in the game, such as crossbows.
Crossbows (note. the crossbow would use bolts not arrows, bolts would cost half the wood that arrows do as they are much shorter) would provide an alternative to the bow for people who struggle to aim with it. While your aim would drastically increase with a crossbow, so would the reload time, this would stop it become op. Its upgrade would be semi auto one (the ancient Chinese did actually build these: http://en.wikipedia.org/wiki/Repeating_crossbow or http://www.youtube.com/watch?v=lR0FXZe2_64 ) or a military grade one (like the one you get in COD).
There should also be knives, solders do not carry hatchets as their close-quarters weapon, they carry knives. the first one would just be a crude, handmade one, but with its upgrade you could even add ballistic knives as the mechanism is not too complicated.
Spears should also be added because when you engae an animal with a mele weapon it is able to bite you, however with a spear it would not be able to do that easily as it is further away, this would mean that arrows/guns would not be the only way to engage animals/monsters without being hurt.
Shields could also be a good idea, they would be espically effective agaist a bow, crossbow, mele weapons and would offer reduced damge against handmade weapons. Its upgrade could even be riot sheild which would be able to stop a few bullets. This would add another dimention to the combat.
Also the bow needs an upgrade, all the other weapons do, revolver - pistol, pipe shotgun - shotgun. They should put in metal bows which you could add attachments too, or a long bow which would do much more damage but have slower reload time.
Thanks for reading, please add more ideas in the comments.