1) minerals, metals.. this is not Fallout (F1,F2, FTac., ..). Only mines in original Fallout universe were uranium (BH) and gold (Redding). So replace those resources with something more postapocalyptic (junk in cities, el. parts, parts from cars, broken weapons thath could be founded in some stores,...).
So scavenge yes (fallout), mininig no (ultima online).
2) "The path is the destination!" phylosophy. Lets make scavenging (or mining, if you are addict to hammer) more entertaining, and people would like this part of the game, instead of thinking about bypassing it.
In my previous post i suggest that players abilities should supercede characters statistics.
Short story: Group of 3 players: Lordus, Sarakin and Bantz entered "abandoned mine" (you can use current mine maps). They know, that there is not any resource left, but mining machines contains of some important parts that could be used in laser weaponry. They have first to repair elevator.. (but they need some parts => INVESTITION of lvl 0 stuff), then they moved to underground level. Then they meet group of wanamingos. They are very though, but very vulnerable to knockback weapons. Lordus and Saraking use their shotguns, to knock them back, Bantz is last defence with his knockback perked hammer. They did not kill any beast, but they succesfully run through the mine tunnels to the doors with mining equipment. Their weapons are out of ammo, and they dont have many AP left, but with last Banz knockback attack, they throw wanamingo back from the doors, Bantz close the doors and Sarakin use his lockpick skill to temporary lockpicking the doors, so they are safe now. They heal their wound and prepare for deeper undeground level, because they know, that more deeper, better and more of mining equipment is there.."
This is the way, how scavenging should be implemented. NOT Better hammer => more ore, not 90 percent in one skill, 90 ores mined..
If this could be placed in some hierarchy: lvl 0 stuff (shot gun, knockback shotgun shells, lockpick tools, rope, ..) needed for lvl 1 stuff ...., you dont have to afraid of huge amount of high tier weapons, because even group with tier max stuff would fail to get tier 2 or tier 3 stuff, because tier max stuff is good only to PvP, not for harvesting. So players (factions) would have to invest time to other than max tier stuff.
Players could barter with their different tier stuff if someone need something, players would need cooperate with another to succeed...
OR current way : hammer and rock = ore. ore and workbench = weapon..