I have logged a lot of miles in the past three years and most recently have returned from Hawaii to my current home in England. I had no troubles carrying a takedown recurve, lots of arrows with broadheads, spare broadheads and three knives.
I packed my arrows, spare broadheads and knifes in an arrow tube. That along with some fishing and camping gear went into a duffle bag. I packed my three piece recurve in the middle of my hard suitcase with my cloths for protection. The bow was in a bowsock. Everything made it without any issues and without any damage. The reason I carried my equipment this was is due to the weight restrictions the airlines have put on travelers these days. If I remember right, most airlines restrict travelers to two bags at 50 pounds a piece for economy class. If you do decide to buy a hard case, consider the size of the hard case so that it can be packed inside of another bag so that you can take advantage of carrying two bags if you need to. If I only have to carry enough that can fit into one suitcase, I will pack a spare duffle, in case I find something I just have to bring home with me.
I carry a knife with me on every trip I make. I simply pack it in my toiletries bag. To date, knock on wood, I haven’t had anything taken. Ok, I think I just jinxed myself by saying this out loud.
Hope this helps. Good Luck, Jack