As Szara said, the “this item conducts electricity” tag only matters for armor if you’re trying to beat things to death with it. When worn, it behaves exactly like any other armor that doesn’t explicitly block electricity. I believe that rubber gloves can protect you when hitting electrified enemies with a conductive weapon, and rubber boots can protect you from electrical sparks/crackles, though not directed electrical bolts.
As far as the game is concerned, a basement is a basement. Does it contain an appreciable number of spiders? If so, feel free to call it a spider basement. The ones most people mean when they say “spider basement” are pretty hard to miss, as the entire room will be filled with cobwebs, spiders and spider eggs.
Coverage is a percentage chance that incoming damage that hits a protected location will be blocked by that piece of armor. I believe they are checked individually, in sequence, from outermost to innermost. If you’re wearing, say, a hard hat, which has 80 coverage, there’s a 20% chance that an attack to your head will completely ignore it, and go on to either do damage to your head, or check against the item of clothing under it, such as a helmet liner. Assuming the attack fails to bypass any part of your armor, I believe the damage reduction for each piece stacks additively.
Needless to say, getting 100% coverage is very desirable. You can be wearing full military kit, and all it takes is one bullet bypassing your 95% coverage army helmet to end your run for good.
EDIT: I just double checked, and the PBA mask has a pretty decent 7 environmental protection when turned off, which is generally enough to protect you fully from smoke inhalation, but not necessarily stuff like toxic gas. Turning it on increases it’s EP to 30, which is enough to completely protect you from airborne toxins of any kind. (Though I think the radioactive Hazy Clouds will still irradiate you.)
