Some items with crafted attributes can be acquired throughout the game. The most common ones are probably swords. However, note that some enemies are immune to the bleed damage that swords excel at in case you want to go that route.
It's a great starter weapon though.
So, no you don't need to craft. It just makes life easier for a fighter.
Also note that crafting is important for many lore related quests, but not essential to beating the game.
You can also buy many potions and items useful for fights, but alchemy makes you much better at it.
I'm also usually not very keen on those additional systems, but since they're used in dialogue as well as I don't mind as much.
About throwing weapons, some people say it works but I have never tried.
Note that you don't need throwing skills for nets and bolas