Can we make an Infinite Hp for all soldiers on the battlefield?
Sure you can boost HP but taking damage still puts your soldiers out of action for a while.
Do you think its possible to make it so your soldiers don't take damage even when hit?
Just use the option to modify health, and use the * key for Super value, all while in the mission. As long as you don't get so low that you're cutting into their "actual" health value (which should take a looooong while), they will not require healing time after missions.