Oh, man. That really sucks but Old55 is right. That could have turned out WAY worse. Reciprocating saws have always made me super wary. They are just so wild and powerful. Wrong angle and you can send the thing flying. I've also seen guys who keep cluttered workspaces trigger them accidentally while they were laying on the floor and nearly lose a chunk of their foot (improper footwear as well). You are right in that they should have some kind of guard. It'd be hard to engineer without minimizing functionality though. I'm glad you are okay. I was worried you might have experienced one of my worst fears... losing a finger. :-O

Yep, that's a no no when cutting rod. Wrap some electrical tape over the cut mark, remeasure it, start with a slow speed if it's a variable speed saw. If it isn't, trade it in for one. The tape will keep the blade from bouncing off the threads on the rod. Glad you got away with just seven stitches.
Nice display cabinet by the way.

Nice job on the case, Space.