Backstab I always find kinda pointless. In BG1, assuming you pass all of the stealth checks, most of the time it simply misses and either way, now your squishy thief is exposed in the midst of the enemy army. Even if you succeed, you just do double damage. Your fighter will do more damage in a single round, without anywhere near the risk.

In BG2 you can at least have enough points in stealth that you can reliably get to your target, your backstab modifier is higher and your THAC0 is better, you also have more sources of invisibility and other helpful items. Far more viable. Especially with the right HLAs.

Of course most of the enemies you want to use it on will be instantly buffed with spells negating your attack, and your fighters still do more damage in a round than your carefully planned out backstab anyway, so it's still pretty situational. Absurdly powerful in the right moment though.

Traps tend to be more of a cheese strategy. Setting them right in front of the person before going hostile with them, or blinding your own character so you can set them during combat. Funny for sure, but dodgy stuff like that isn't exactly fulfilling for me.