2nd.
First of all, thank you so much for giving such a thorough overview. Some follow up questions.
Any idea what about the game design causes those trap builds? Why does combat splatter so easily?
Okay, so, it's been a long time, but the big things are this: There's a lot of Charms that are just bad ideas to take, and a lot of Charms that are game-breakingly amazing, and also worthless, for reasons I'll explain:
A bunch of extra hit points? Pretty much useless once you get a bit into the game, so much damage is thrown around that it's not worth buying Charms for health levels. Particularly with Lunars around, who can throw absurd amounts of damage via having 15 strength and such nonsense, and Solars, who could pretty cheaply pull a combo of "I double all threshold successes for the purpose of determining damage, and then I double all damage", because Solars weren't even pretending to care.
There were Charms with keywords like Shaping, Poison, and Crippling that do stuff, often uncontested or with a bonus to the rolloff to just remove your arms or blind you forever or break your back, or melt your guts from the inside out, or turn you into a goddamned duck uncontested. One shaping effect Sidereals had was "kill anyone outright" or some nonsense.
Keyword defenses were super easy to get for everyone but Sidereals and Dragonblooded, and would shutdown the autowin effects 100%. So you have players buying these badass OP Charms expecting to break people's backs like Bane or Avada Kedavra them, and then the ST has to have their NPCs have shaping defenses, turning off the power the PC bought so there can be meaningful fights, and the one PC without a shaping or a Perfect Defense detonates when they get hit by an Exalt's combo, or turned into dust by some stupid shaping effect.
You need to buy keyword defenses so you don't auto-die, perfect defenses for both Step 2 and Step 7 of combat so you have two layers of panic buttons, for when you know something will kill you if it hits (Step 2) and aren't sure until after you see the roll (Step 7). Step 2 also dodges deletrious effects attached to the hit. IIRC if you put a shaping attack on something Adamant Skin blocked, you could have the Solar take no damage from the hit, but still be turned into a duck.
The system is so fragile, so rocket taggy, so poorly designed that every single splat has a one-true build you have to work towards, and IIRC it takes about 150-200xp before you can just buy the powers and effects you want without worrying about the integrity of your character in the system.
Essence regen effects were also scattered around, and having one while your opponent doesn't means you win, because you spend less on the same stuff that they do (This is also why Solars always won, they had much cheaper perfect defenses and much cheaper and better damage, so they could force you into certain mote spending paths, tap you, and then explode you with their four times damage nonsense).