You can generally play through to the final boss without a wiki - there’s a guide NPC that can tell you crafting recipes with items you show him, and generally the NPCs hint at things. There’s a few esoteric moments that might hinder your progression that were established during the early days; however the game is fantastic at driving your curiosity and you’ll keep discovering stuff.

Most likely a mix of both

Can confirm. Have been using it for a while, works like a charm.