I was the one that said it does 8 damage per upgrade, but that's 8 damage for a unit being under the storm for its entire duration, not 1 tick. It's 14+1 per time it gets hurt, and 112+8 for total duration, since storm hurts a unit 8 times if they sit under it the entire time. Upgrades do not change the duration.
Upgrades to storm will only affect the player that you have it upgraded for. So if you set the default for unused upgrade 60 to 50 upgrades, then all players will have the 50 unused upgrades; if you set default to 0 and that player to not use default and to have 50, then only that player has the 50 upgrades.
I'd recommend not setting default to 50, since it also affects a lot of things because psi storm, a list of which I'll find and post here later.
EDIT: Here's all the significant other things it has an effect on. You can set all the bonuses to 0 or whatever you want except for building armor, critter armor, and psi storm damage.
QUOTE(Kenoli)
- Photon Cannon damage
- Missile Turret damage
- Sunken Colony damage
- Spore Colony damage
- All building armor
- All critter armor
- Infested Terran damage
- Scourge damage
- Spider Mine damage
- SCV damage
- Probe damage
- Drone damage
- Psionic Storm damage