Ok, so it looks like you've got a few things going on. I've been staring at the transmission section of the shop manual for a week straight now so let's see if I can come up with something that makes any sense and might be useful.
1st, you've got the shifter plate for a car with a console. Doesn't matter today, but you might need to know that in the future. That dial indicator plate with the PRN0.L on it needs to come off though.
The shifter ball do-dad is just hooked to a little lever just under that plate. It's called the detent pawl and it slides along on a detent plate with different grooves cut into it like the side of a key. This is what keeps the transmission in gear and normally keeps you from just pulling it from P to R.
So you need to pull the plate off and get a look at it and make sure that it's sitting in the grooves properly and that it lifts up when you flip the shifter ball thing. You should be able to slide between some just fine, like D to N but you shouldn't be able to just pull it into R. Once you're looking at it you should be able to see how it works.
The kickdown looks like it has a lot of slack in it, but you need to jam the pedal down and see how it looks then. With the pedal on the floor that line should be tight and the kickdown lever pulled all the way forward.
I think the linkage bolt is fine if that's where it needs to be for the shifter to work properly. I think it's missing a washer to take up some of that play (and now I see that I think mine is too) but as long as it's in the adjustment range I think it's fine.
That wedge shaped piece on the side of the transmission where the kickdown linkage and the shifter rod attach is the NSS. Though that does look like it's wire hanging down on the other side of the transmission. Normally that wire should go forward and straight up the firewall to a connector hanging out just to the driver's side of the center of the car.
That's probably plenty for one post. Start by pulling that indicator plate off and looking at your detent pawl and you should be able to see what's letting it slide into Reverse from there.