Agree...don't give up. During fur boom years, I used to get so upset over losses and theft. It was an interesting battle I had on my hands sometimes. During good market years, they would steal my coyote or fox and my trap. During poor market years, they would actually leave the coyote (shot to heck and worthless to me) and still take the trap. I went to double staking and earth anchors, wanted to at least give them a hernia if they tried to pull that trap anchor out again. Then new kick was to run over my trap several times with their trucks, ruining my trap completely and still taking my catch or shooting it full of holes. This was all on private property also.
Theft is just part of the game...and unfortunately it comes from both an uneducated society about woodsman's ethics and respect for each other and each other's property. It makes you think sometimes about how you don't go shooting up or stealing their bird dog, or their gun, etc. but they can't seem to respect your equipment and rights to be afield just as they are. Nothing you can do about it but don't buy into their game and play by their rules. It just happens.
Learning is also part of the game. I swore I learned a lot by reading books, magazines, talking to others, etc. But none of that beat actual field experience either. First time you come upon a coon catch that pulled out of the set long before you got there...it is quite an experience. The completely torn up set, the chewed up branches, dug up ground, etc. it can look like you had a wolverine or lion at your set...then you dig around a little only to discover you lost the trap, stake, and all. Or, maybe you find your trap with a little toe and hook-shaped claw still between the jaws.
Coons will give you a quick lesson in trap anchoring. I firmly believe that pound for pound they are one of the strongest animals we trap for their size. They also have rubbery feet, can grasp with all four feet, have hind feet that rotate complete 45 degrees opposite direction, can bite like any animal, etc.
Again, don't give up. Chalk each incident up to "learning" the hard way. Many have done this the exact same way you are unfortunately having to do yourself...and have ended up outstanding trappers as a result. You'll get there, don't worry.
Jim-NE