Hamas had a somewhat similar strategy to try and bankrupt The United States Israel by repeatedly launching ~$500 dirty rockets into Israel so the Iron Dome would intercept them at $15,000 per shot. That idea could work under different circumstances.
No, but the US currently gives Israel $3.8 billion/year for military funding even though Israel is a wealthy country that frequently runs a budget surplus. The Iron Dome would have to be fired 250,000+ times to go through a single year of the US's donations alone, so the strategy would effectively be plinking away at the US's money.
I think expecting those hummer clones to last very long is fanciful thinking. If it's deployed against a force that doesn't have access to enough airborne assets they might be useful.
There are air-dropped area denial weapons designed to eliminate all tanks within a large radius that would certainly destroy a hummer clone. I can't remember what it's called. The USAF used it on a couple of iraqi tank positions with a 100% kill rate. They might get off one launch of those little drones, but reloading won't be an issue for the launch crew.
There are also several other smaller air-dropped and cruise missile delivered vehicle killers.
Yeah the mobile deployment vehicle like that would certainly be vulnerable. If they modified the system so infantry could carry a single drone each and a group could have a shared mortar-style launcher and a dedicated "pilot", then those could be very quick to deploy disruptive little things.
Time to unlock the Point-Defense tech tree
Although this is the inevitable next step for drones, it's still a terrifying new reality. The cost of a few dozen drones to take out a 9million dollar tank could economically cripple an army.