Need installation instructions for sliding shower door...probably #5475. When reinstalling, the inside door is swinging with nothing to secure the bottom.

You need to provide more detailed info on your shower door.
Sliding or swing out. Bottom rail on the door or bottom rail on the shower stall curb. A few photographs would also help.

The installation guide is here:
http://www.us.kohler.com/webassets/kpna/catalog/pdf/en/1201264_2.pdf

and bottom of this page you can call or send message:
http://www.us.kohler.com/us/Levity-sliding-shower-door,-74-H-x-56-5-8---59-5-8-W,-with-1-4-Frosted-glass-and-towel-bars/productDetail/Sliding-Shower-Doors/914746.htm

The top rollers should have adjustments on them to bring the door to horizontal as it swings accross the track.

Start with door in the middle and adsust by seinging it to both sides.

A hardware store will have replacements, if not go to Maax website and order there, replace them all.

curved cut glass will not always be the exact dimensions though they may look identical there should be several set screws on both the door glass frame and the shower glass frame that can be loosened and reset to make the door fit and close and open more properly without seeing the showwer itself i can not tell you exactly where they are but they should be either visible or behind a facade piece of metal frame

no you need to replace the door,they are factory pressed.

you going to need a 2' square aluminum tubing for the corner.
the tubing need to be bolted to the floor. and bolted from the 2 upper rails. then you can attach the doors.
make sure the tube is well secured. the door weights about 12lbs-15lbs each ( depended on the glass).

Your 4 screws may hold the swing piece to the slide piece. You actually secure it to the slide side wall with one of the red screw caps but you can also secure it with 4 screws that screw into the plastic.  You can also find the manual and assembly instructions at littletikes.com

you need to remove the bar from the wall than the slider goes on the bar and than you reinstall the bar again