Someone using something as a human shield makes it into a human shield. Requires just one.

How many soldiers does it take to change a location to a military target?

Could be as few as one. Which is why there's zero tolerance for using such locations.

Ok, does that apply to Israeli hospitals or public venues that had soldiers there as guards?

It's the same rule for everyone.

If the attack on those venues is terrorism by virtue of the civilians there, but not a legitimate military strike despite the soldiers being there, then at the very least, bombing hospitals and refugee camps is terrorism too even if a few soldiers and weapons are found.

There's two related issues. Killing civilians and using civilian cover to conduct warfare. Both are despicable.

Executing human shields is monstrous, and "look what you made me do" is the language of abusers.

Right, though I'd put more blame on those, you know, using human shields. They're the ones putting the humans between you and your enemy to begin with.