I don't know about the third one, but if you want your soldier to take a lot of damage, you spend points on fitness until you're able to you unlock immunity. Then you max out Immunity. --- I was the turkey! Me!
Shock Trooper is really a waste of time IMO. Once you get Colossus X armour and max out Immunity, nothing will be able to touch you anyway, even on Insanity. I could go toe to toe with a Geth Colossus on Insanity with my Commando and barely take a scratch. Even more defence and health from the Shock Trooper talent would just be overkill IMO, whilst the extra damage output from the Commando talent is very useful on Insanity.
12 Pistols 00 Shotguns 11 Assault Rifles 12 Sniper Rifles 07 Combat Armor 00 First Aid 12 Assault Training 12 Fitness 12 Singularity 12 Commando 12 Spectre Training
There you go, you can get all the Charm and Intimidate points you want for free with 3 playthroughs. Still if you want to move some points around, then take them out of Spectre Training or your back-up weapon, Pistols. You'll get to use you bonus talent twice because of Adrenline Burst, so Singularity is a good choice. You can have Warp if you like as that was the old Gold Standard, but newer discussions and testing have concluded that immobilizing multiple enemies before they can activate Immunity with Singularity is better than de-buffing an enemy or two with Warp.