If the knife is in checked, hold, luggage, not your carry-on, it will not be confiscated at the airport. They will not care. I have travelled to Norway, Sweden, the US, Canada, Hong Kong, and Namibia, all with different airlines, and had a knife of some sort, often a sheath knife, sometimes even a parang or axe, in checked luggage without problem.
Trying to hide things in carry on luggage is a losing game these days. I had Eurostar security see a Swiss Army knife in my bag, and through shear incompetence fail to find it and just let it go through, but the airport staff tend to be more thorough. They will keep going till they find what they are looking for. A friend had his titanium Spork confiscated and another was held up while they searched his wallet till they found the blunt leather work needle that he had forgotten was there. The x-ray gear is very good these days. If you pack things in a metal container and they can't see what is there, they will have you unpack it all to satisfy themselves. Some flights now allow small knives, but others don't. I like my knives, but have never needed one in an airport.
Camping is possibly a "good reason" for having a locking or fixed blade (legally they are the same). Hiking in itself is not going to be a "good reason" in the eyes of the law. Lots of people hike without even as much as a SAK. Hiking is just walking after all. Also if you are staying in hostels you have both less need of a cutting tool and will be in closer proximity to people with whom you "might" have disagreements.
If you want to be 100% safe you would be better off getting a non-locking folder (Boker Techtool is fantastic), however, the next best would be a non-locking folder in your pocket and a Mora fixed blade deep in your pack. The least good would be the 3.5" Cold Steel in your pocket. My reasoning in this is that a 4" fixed blade is better for food prep than a 3.25/3.5" folder, it is better for fire wood prep, it can slice bread much better, all things you do when in camp. When you are not in camp you don't need it, and it is buried where it is not readily accessible. A locking folder in your pocket can be seen as an accessible concealed weapon. This isn't legal advice and but if I was stopped and had to explain the presence of a knife, I think I would have a better chance explaining the Mora than the CS.
The chance of you being stopped and searched if you are fairly clean cut and presentable is pretty low. If you are hiking through the countryside it is even lower. The risk is in the unexpected. Being in the wrong place at the wrong time, or being reported by some member of the public. Less likely to happen in the countryside, but some popular tourist areas do get patrols.
When I was young I thought exactly the same way about locking vs non-locking, I also thought my Cold Steel Voyagers were fantastic and wanted to carry them all the time. I ran risks. I even ran some risks with a Large Sebenza. I also had two near misses with police that scared me into being a lot more careful. I have since learned that my CS Voyagers were not so amazing and that a lot of what I need to cut can be done with a non-single handed non-locking knife. Maybe not as safely and not as conveniently, but it is nice to be able to use my knife in front of people without a care or concern.
