OMG, your english is worst than mine...
Vehicle Gun Turrets are made for use in the very beginning, their damage can be upgraded in the Bullet Damage upgrade and doesnt consume energy, in the first time you place the V.G.T. the energy is charged to the max and dont recharge after this, you can imagine the energy bar as how much ammo it has.
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About the Lasers, the MK1 is indeed less efficient than a vanilla laser, BUT, Laser Damage upgrades Works this equipment. A single laser mk3 with full Laser Damage Upgrade can deal insane amounts of damage.
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Iodine has a chance of 1% = 0.01 , but the game shows 0.0
You need many buildings to produces few iodine powder.
The iodine chain is intended as a workaround if you dont have uranium.