1. Yeah, it does look a bit weird. Definitely to be fixed.
2. I really ought to fix that as well.
3. Definitely to be fixed, unless I'm pure evil and deliberately place harmless spikes among harmful ones. Which I wouldn't.
Also, those are the things that the armored roaches throw at you, though they defy gravity for whatever reason. Mostly.
Being a Laboratory, I guess it was an experiment?