Keezer/ Fermentation Chamber is beginning to rust

Picked up a chest freezer and temp controller about a year ago and began using it as a fermentation chamber during my brewing seasons (i.e. when I have the time and resources), then in the off season, it's a beer chest. Just recently got started kegging, so now it's a keezer.

I noticed right away that the amount of moisture collecting inside the keezer is pretty substantial. As a ferm chamber, I was able to manage the extra moisture with Damp Rid. However, the moisture is beginning to collect on the sides and after a couple of worn o-rings caused a couple of my kegs to leak and fill the bottom of my keezer with my precious homebrew, rust is beginning to eat away at the joints of my keezer.

So the questions:
1) How do you guys handle dehumidifying your keezers?
2) I cleaned up rust pretty well, but can't help thinking that it's just going to come back unless I get the moisture under control. I'm also considering repainting the inside with Rust-oleum and sealing up the joints with silicone caulk. Is there a better way to prevent rust inside the keezer?
3) Is this pretty common problem others have experienced with their keezers? I've seen posts regarding the humidity collecting, but haven't seen anything that suggests I needed prep my chest freezer beyond hooking up the temp controller.
4) I have about 4 taps going right now, but now I'm out of a ferm chamber. Am I really going to have to suck it up and get another fridge/chest freezer? Just wanted to know if you guys also ended up getting multiple chest freezers or cooling units to handle the demands of our hobby? I'm running out of space in the garage and SWMBO keeps buying more crap!

Any thoughts you all might have would really be helpful. Didn't mean for this post to be so long, but I've been thinking about this stuff for a few months and the rust build up was a good excuse to post it all. Thanks guys!

I keep a "new unused" baby daiper in the bottom of my keezer to soak up any spills or condensation. As far as the seams rusting...that just seems like part of doing business w/ keezers that I don't care much about it. I do use free or cheap freezers so I don't care much to be bothered painting or sealing the seams to fight the rust battle.

I use a dehumidifer with a computer fan to blow air over it.

I used some POR-15 on my Jeep's bumper. It was pretty rusty. Sanded down a lot of the rust, put on the POR-15 as a primer, painted over that...rust hasn't come back. It's been a few years now.

http://www.por15.com/POR-15-Rust-Preventive-Paint/products/1/