Your caster being around 2 degrees negative from where it should be will definitely cause your car to be more prone to wandering. Too much negative caster will not allow the car to maintain steering on-center, which will cause wandering. It will also amplify any issue you may have that could cause a pull, including road crown. It will also cause your steering wheel to snap back to center aggressively like you describe. If you can get your caster back where it belongs, you will probably notice increased effort when steering, but the wheel will no longer snap back center like that, and your wandering issue will be gone as well. Since your caster is not adjustable, your alignment technician will have to start looking for bent parts, such as control arms, strut rods, or strut plates. Oftentimes, when the negative caster has increased like this, it was caused by someone crashing the car into a curb or parking block rather forcefully, bending parts and changing the caster angles. In a nutshell, I believe all the problems you are noticing are caused by your excessive negative caster, and the negative caster was probably caused by a previous owner crashing the car into a curb or parking block (probably a parking block since you don’t have a ton of cross caster) and bending parts that shouldn’t be bent.
Mark9207 is correct and my line of thinking from the get-go was that both front wheels have been shoved backwards a couple of degrees due to a curb strike or possibly a collision. I would think that if it were the latter though that the camber and toe would be way off.
It could also be that in the event of a past collision that someone yanked the camber into place and then set the easy to adjust toe while dismissing the caster. Dismissing the caster is a pretty common trait that has been around a long, long time…
Thanks, it is really starting to make sense now. Its easy to blame him because he’s got no way to defend himself… buuuuut my ex was not the greatest driver and definitely a horrible parker. Great guy, no idiot, but not a very conscientious driver. We had the car from 55K, its now at 71K and he put the vast majority of the miles on it. He jammed the right wheels into the curb in front of the house all the time and left it parked that way – and what do you know – the right front and right rear toe was off. Coincidence? I would not be surprised if he parked similarly at work (there are straight spaces with a curb in the parking lot at his work). He also always turned the wheel while the car was not moving which annoys me, perhaps unreasonably. The car DEFINITELY used to drive better but I have so far been unable to find the alignment sheet from the previous aligning about 8-10 months ago for comparison.
A collision by a previous owner is also very plausible. At 55K I was the fourth owner. There were no accidents reported to CarFax at the time of purchase, but of course that doesn’t necessarily mean anything. And at one time it was sold at auction. I sometimes worry my car was like a poor little mistreated orphan that no one wanted.
Oh yeah, and this is the same guy who put ATF in the oil on my previous car!
The alignment specifications on your print out are for power steering. The caster setting on the manual steering Rio is less than what your car has. Less caster allows for less effort when turning at slow speeds. The trade off is less “return to center” force and the feel of wandering.
BTW that steering wheel kick back at slow speeds while braking on poor pavement (ruts in the asphalt from truck traffic) occurs on many cars, not just cheap ones.
@Nevada_545 Oh cool thanks. It makes so much sense that they would want to make it easier to turn the wheel. I’ve learned a lot, thank you all 
Did someone put custom wheels on the vehicle that place the tires a little farther out than the stock rims? That will have an effect similar to changing the camber. It puts the center of the tire’s contact point outboard of the tires steering pivot point.
I am reading this post for the first time, and Nevada was the first to catch the fact that caster is often different with manual steering than with power steering.
Not many cars are available with manual steering, but those that are, usually have two caster settings available, neither are adjustable though. On Toyota’s where PS was an option, there were three studs and nuts in the upper strut mount, but 4 holes in the top of the strut tower. That is, if you open the hood and look at the mounting nuts for the struts, there is an empty hole. If the front hole is empty, the strut was set for PS, if the hole in the rear is empty, the strut is set for MS.
Your car probably has something similar. It could be at the top of the strut tower or it could be in the trailing arm or sway bar, done with different thickness bushings.
I’m not recommending that you change anything, but if you really wanted more stability, you could have the caster changed, but the downside is that the car will be more difficult to steer at low speeds. If you have the strength, then you might consider this.
I still think it could be a dried out ball joint.
Nevada_545 was able to find what I was looking for. I suspected that more negative caster was called for on cars with manual steering to make it easier to steer (more positive caster increases stability, but makes steering more difficult, which is not much of an issue with power steering), but was unable to find specs for this. Based on those specs, your caster is where it should be, but I wouldn’t like that much negative caster and the stability issues that come with it. This may be something you have to learn to live with as long as you have this car.
Thanks everyone. I definitely wont try to “fix” the caster now that I know its ok. As it is, it can be rather difficult to turn the wheel when doing a slow sharp turn or parallel parking. I am amazed to hear that it could be made even worse. I can easily live with the weird steering – just adds more character to my baby