Carry-on vs. Hold luggage vs. shipped package Santiago to It

I fly Seattle to Paris next Monday night and begin my camino frances from SJPP (arrive on 28 June and walk 29 June stopping at Orrison the first night). I hope to arrive in Santiago by 1 August.
Yes, I am very excited and also nervous.
Now for my dilemma: On 3 August I will fly Vueling from Santiago to Firenze and according to the baggage rules of Vueling Airlines, I may not be permitted to carry on my Swiss army knife and pacer poles (which do break into 3 22" pieces each and do fit inside my backpack). If the backpack is x-rayed or inspected these items will be found. So, it costs 25 euros to take as hold baggage on the plane and I would be ok with that BUT I am concerned that it could get lost in Barcelona where we stop for an hour before continuing to Florence. I could also mail a package with the items to the hotel in Rome where I will be staying from August 7th until the morning of the 9th when I fly back to the US.
My priority is not losing the pacer poles but not spending too much to ship, say under $100.
Should I :
1. Try carrying all on the Vueling flight with me and if Vueling insists, check the poles.
2. Make the poles and knife hold baggage now.
3. Mail a package with poles from Santiago to hotel in Rome (ship on August 2 to arrive by Aug. 8.)
OR??? Advice is much appreciated. Teresa

Thanks for the replies. To clarify, I am checking baggage (with poles and knife) on the trip from Seattle to Paris. I am also checking baggage or having "hold" luggage as it is called on the flight from Paris to Biarritz. BUT these flights, I will claim my luggage when I land and the flight from Santiago to Florence will stop in Barcelona briefly and that is my concern, that my luggage will stay in Barcelona.

A friend had a brilliant suggestion that I hadn't considered and that is to mail my poles, etc. all the way back to Seattle from Santiago, and provided that it isn't exorbitantly expensive, that is what I will try to do. My husband will be home in Seattle to receive the package and the time frame doesn't matter to me.

I have to shake my head that I got so caught up in this detail when I am going on faith that the poles won't get lost before I even get to St. Jean. Nevertheless, being able to ask this camino for help has been very reassuring. Muchas gracias. Teresa