I think you're right on target that the majority of Palestinians are also hostages of Hamas.

How do we rescue them, though?

The counterargument would be that left free, Hamas leadership would cause far more deaths even among Palestinians than died through the bombing. I'm not sure I totally buy that argument, but if you follow through this line of thinking, that's where you end up next.

Also, given Israel's frequent use of bunker-busting bombs to target tunnels that it does not seem they could possibly have inspected, I'm not totally sure that Israel isn't willing to sacrifice 20 of the hostages to kill a couple leaders. They're not conducting the offense in the way one would to minimize the chance of casualties among hostages, that's for sure.

So--how do we, even in principle, rescue the Palestinians who are hostages? Everything I've thought of (and yes, I had the same idea) runs into the hundreds of billions of dollars, is counter to all sorts of international norms (albeit less counter than is bombing civilians), and it is doubtful that it would succeed.