what is the durometer of this tubing?

The durometer of our tubing is 50A.

Re: 3/16x3/8 tube, is the od accurate? i already have 3/16 (5mm)x5/16 (8mm) tubing & need a thicker wall. also, is this pure silicone w/ no fillers?

The corresponding id of our 3/16 x 3/8 tube is 5mm and od is 9mm, which is thicker than 5/16 (8mm) od. We are made of food-grade pure silicone.

Is this tubing still considered food safe when food/water can come in contact with cut edges of the tubing (ie no fiberglass)?

I’m not a scientist, but I believe strongly that the cut edges are not going to harm food. It’s silicone tubing. No fiberglass involved.

What is the minimum bend radius without kinking?

The tubing is fairly stiff, I use mine for a steam fruit juicer & it doesn't need to bend much. Of course when it heats up it becomes more pliable, but hot or cold it would collapse if bent to a tight radius. One bend option would be a rigid barbed plastic elbow, but that would severely restrict the flow. There are tubing benders that look like tightly coiled old fashioned screen door springs. Maybe try to pass the silicone tubing thru an appropriate size metal spring type tubing bender & it would support the O.D. allowing a sharp bend and prevent collapse.