Chopping wood was a great way to gain strength, to get to the godly 95 where one could wear a platemail chest. I chopped wood and carved bows for my first month to buy a small house, only to lose it to the exploiters next door in just a few days. That was on top of all the lag and crashes. I was ready to quit but kept going.
GMs and even the UO team dismissed house break-in exploits as "clever uses of game mechanics." Seaside houses were particularly at risk with one disembark exploit.
Some twit at WBB bragged that he had runes to all the cities, when they were already available for 100 gp each on vendors. Gold wasn't as plentiful as now, but it wasn't that hard to get. With 90 lumberjacking I could make 3K an hour from my bows!
Every non-thief had to hide while banking at WBB. A thief would run as far as he could so that an accomplice could loot the stolen item. When guards started returning items much later (1999), there was a huge outcry from thieves that this would destroy their profession. Considering that only the most unskilled griefers were complaining, it was a good change.
I was one of many goaded into attacking a certain thief who discovered bandage healing before anyone else. Originally bandages could be used while remaining hidden, and one could still hide within line of sight. With an exploit to snoop from across the screen, the thief could easily clean out any player, and kill any player who suddenly found himself without a weapon, arrows or regs.
Uzi bows. A certain exploit program could rapidly arm/disarm, firing off an arrow with every equip, hence the introduction of the "You must wait to perform another action" delay.
Scammers mislabeled items on their vendors, to fool those who didn't have item ID wands.
The bottom of Shame was only for the elite. Blood elementals weren't too bad since you could stay behind stalagmites, and monster AI didn't yet include pathfinding. But you still needed 90 archery and tactics to hit one decently.
Deceit's lich lord room was the reward for reliably casting EVs. A mage could safely stay on the ledge, then cast an EV on the pillars that wore down a lich lord.
A GM once took control of a lich lord to give a friend a challenge. My friend won.
There were stories of those who dared to venture into Hythloth 3, sometimes getting killed in one hit from a balron. Hythloth was a dangerous place. There was no help stuck option, no runebooks, no insured items, no LRC, so even if you exited as a ghost, you'd need a gate out even if you did find a wandering healer. Overland spawn was messed up for a long time, so it could be hard to find monsters and NPCs, especially a wandering healer.
Those of us working magery could still do well against drakes, until this was declared illegal. Summon a blade spirit, cast Reactive Armor on it, and a drake would instant-kill itself with its own firebreath.