I'll try to explain a little better based on some conversations I had with USMC veterans of Fallujah (yes, that Battle of Fallujah) and also Mosul (when it was still during OIF/OEF) veterans from U.S. Army
1) Yes, you are correct in your conclusion that at this point in the war there is no possible way to avoid/prevent tremendously bloody and massive casualties even with the best dismounted infantry fighting force in the world. This is mostly due to the horrific amounts of indiscriminate ordinance use all over Gaza making it so that every piece of land is filled with a million different ways that someone can avoid detection against even high-tech methods such as IR/Thermal vision air support. Israel could not have given a better Christmas/Hanukah gift to Hamas if they tried. By doing what they did they (a) turned world opinion completely against them, (b) gave Hamas more cover, concealment, and camoflague then ever previously possible, (c) caused masdsive upheaval and civil unrest even inside of the political elites of the very same countries that are very blatantly controlled by Israel...Biden's internal team is openly and publicly revolting against him...France, Spain, etc. have their literal leaders now trying to distance themselves from Israel evena fter publicly declaring support, (d) ensured that Hamas will never have to worry about hitting recruiting goals unlike the U.S. and other western militaries, (e) finally dispelled the illusion of invincibility of the Israeli military to all of their Levantine neighbors whom only really settled for peace because they were under the previously false belief that Israel is a Goliath of some sort that the Levant cannot beat.
2) First, see below:
Timestamp is right around 2:10
But notice that the Marines are basically taking overwatch.
Keyword here is Overwatch (a word ruined by Blizzard game devs BTW). If Israel had been smart they should've followed a plan kind of sort of like this:
(a) Insert light infantry under cover of darkness during nighttime because you can afford Thermals/NODs for your guys but Hamas obviously cannot thus giving you a significant advantage >>> (b) Your light infantry must stealthily infiltrate trying to draw as little attention as possible, they are not supposed to be the killing force here there is a bigger plan than that >>> (c) Of course since your light infantry is totally (supposed to be) the elite fighting force that means they planned things out long ahead of time and knew exactly which building to pick as the 'base'...a building that's nice and tall, strong structure, and most importantly is actually out of the path of the later armored assets so that your air power is never forced into a position where they must do extreme danger close fire mission...*if I was Hamas and I realized that I am cornered with no way out then I will fight to the death and force you to call an airstrike that's not only right on top of your own tanks but also when your tanks are sitting in front of the building occupied by your light infantry scout platoon so that all of you go down with me* >>> (d) Once the attack commences the next morning have your mechanized or Stryker (don't know what's the equivalent in other militaries since Stryker Infantry is a US Army special deal sort of) infantry first dismount before they reach the area then split them up appropriately so that part of the infantry is ahead of the vehicles, part of them is hugging the vehicles, and the last part is protecting the rear of the vehicles >>> (e) sooner or later Hamas will engage the vehicle column...if Israeli infantry did their job properly then the first contact will be made by the guys way in front of the vehicles at which point the overwatch force will be directed to the action and can snipe or possibly call in an airstrike/artillery barrage...at the very least watch where those guys are running away to so that you can give chase...if Israeli infantry failed then Hamas will initiate a attack at the time of their choosing, however, regardless of who initiates first and who has the more favorable conditions at first contact the overwatch team has the same job. which is to call in air support/artillery and/or simply engage the target themselves if that's the better option >>> (f) once the vehicle column has passed now you bring in an occupying force...believe it or not but Military Police and/or Mortar Platoons are perfect for this role. Keep in mind that one of Military Police's responsibilities in the U.S. 82nd Airborne Div is to protect the roads that lead from base to a frontline so that the grunts can fight on the battlefield without having to worry about an enemy saboteur behind the lines. Mortar Platoons are similarly good for this job because the only thing both these guys really need to do is to sit inside of some buildings and make sure that there's no saboteurs behind the lines. >>> (g) wash, rinse, and repeat this formula basically always insert an infantry force as overwatch prior to armored assets coming in, then slowly move the armor and fight the enemy or scare them away, once the armor moves past a designated point then bring in troops less suited for intense-combat to sit inside the buildings that you passed by so that the enemy doesn't do that thing where they pretend to run away only to come back. >>> (h) eventually you have a 'cleared' city...hopefully.
