It's not official, just compiled from the BIOs. Check the Joe Robinet's pack - it states "Large Knife" vs just "Knife" for others. But you might be right about Khukuri being just a regular knife, and something like machete - a large one...
Update: In the Ep.1 at 19:40 Joe is using a simple mora like knife, though. Also his tarp looks different from Lucas one, called in his BIO "Ground sheet". So that's another candidate for item #20 then.

For the bow. I agree that with the fishing line and random wood it could be underpowered, line is stretching with time, and so on... However I don't think the game, possible to take there, could be larger than a rabbit. Anything larger most likely will engage with you in "close combat" by itself, so you could score a meal much easier than wandering in the woods with a bow if you got a heavy spear with body stopper and some courage:


Surely, even a simple bow or crossbow making requires specific knowhow, but it is doable. However, if you never made a serious one - it could be more beneficial just stick to what you are proficient with (i.e. make a sling, maybe an atlatl, or just a cross-throwie...). Anyhow, the location seem to have animals aware of hunters, so traps will be way more effective.