Here's what I am thinking if you disconnect the fans. I have never done this, so I am not sure it will work, you are right that the fans circulate the cold air from the freezer, but there will still be some convection without the fans. Since cold air is heavier, it should get to the freezer, but much more inefficiently and perhaps slow enough to raise the temperature of the fridge. Also, since the air will be more stagnant, you should also be able to control the humidity better.
If it is still too cold, you could try buying the same type of thermostat I got, well, it should be here tomorrow, and control the temperature better with that. Put the thermo-sensor in the fridge part and set it to 55 degrees. I'm thinking that would work. If it doesn't, you could still use the thermostat in a freezer or other cooler.
You are correct about the inner mechanicals of my freezer. So far, my freezer is working well without the thermostat. I just plug it in for ten minutes, get it down to 45 degrees and shut the lid. So far it has taken 24 hours to reach 57 degrees and I just plug it in again for ten minutes. Soon, I won't have to worry about that.
I started off with a bowl of water in there, but the humidity rose to 95%, probably because I have so many new cheeses in there. I removed the water, plugged it in and let it run open for a while and got the humidity down and then closed it. Right now it seems to be maintaining around 87% humidity. As the cheeses dry, I will probably have to add water again.