@James Snowscoran Redundant means duplicate or overlapping. None of the skills overlapped. It was a deliberate point of the game that differently skilled characters could succeed by their own means.
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The point of Barter was to convince/or connive a higher value for trading the PC's goods to others.
Gambling was disappointing, in that it was a skill for winning, instead of a skill for cheat detecting. But it was a way for the PC to easily (and legally) acquire caps.
Throwing was a supremely worthless combat skill
What game did you play, that the grenades weren't a godsend? ...and used any time the enemies clumped together on the field? Of course there were also throwing knives that used the skill.
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I think Sneak and Steal also qualifies as really niche.
Steal was useful for stealing... from anyone; and you could give them stuff too—sometimes unwanted stuff.
Sneak was superb. It hid the PC's actions from NPCs. You could sneak a peek into someone's containers—while they were in the room. In combat, if you started the round in Sneak mode, and killed your opponent on your first turn—nobody nearby would notice it.
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First aid was just a gimped version of doctor
First Aid is not as you say. Fallout 1 & 2 had two medical skills. First Aid was for healing hitpoints, and it gave 25 XP. First Aid allowed for any character style to have access to some level of basic recovery without consumable items. First Aid also could be easily (and permanently) improved via books (with no —long term— need to invest skill points), and received a bonus when using a First Aid kit; this bonus was consumed with each use of the item.
The Doctor skill was an expensive development path; it could not be improved with books. To be a doctor, the PC had to invest skill points to improve it; and obviously this takes away from other skill development. It's a slow skill (depending on injuries; the more injuries the longer it takes). Its intended use is to correct crippling injuries —this is beyond the First Aid skill. Doctor gave 50XP per successful use, and (like First Aid), there was a consumable Doctor's Kit (bag) that provided a bonus to that skill with each use of it.
Both skills were limited to three uses per day. What this means is that the PC had six opportunities per day, to heal their character or NPC party members (or anyone else!), but only three of these (not six) are attempts to undo crippling injuries. The player has to decide who to risk using the Doctor skill on, and then use the First Aid for anyone else.
It was easily possible to have 80% first Aid, and 35% Doctor. The Doctor skill was a poor (usually less reliable) replacement for First Aid, but it could work to just heal hitpoints in a pinch... but it's a waste, because there could be crippling injuries later on that day, and the attempts would have been used up.
Any PC with 80%-150% in Doctor skill had certainly built their character as a Doctor, instead of a Weapon's Specialist, thief, or diplomat. Such characters serve well as medics for a whole troop of combat NPCs... because those are the ones that would probably be doing the fighting.
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The core problem is that F1/2's SPECIAL system of character creation had a lot of pitfalls for new players. It's very easy to come out of it with a supremely gimped character if you don't know which skills are worth tagging and what traits are worth picking ahead of time. Then you find yourself able to neither beat Klint in combat nor talk your way out of fighting him and quit before finishing the tutorial.
This is a non-issue for anyone who read the manual. Certain skills are cautioned as being for certain build types.