I don't know how the hell you killed a level 16 Drake at level 3 with no real useful abilities in the tree unlocked yet. I'm playing on Death March but I still struggle with things only 3-4 levels ahead of me, I imagine if you got hit even once without Quen up (or even with it up) you'd die. Impressive.
I agree with everything you said though. Lots of games tell you there are tricks/weaknesses for certain enemies but those weaknesses make no real difference and you just spam whatever your most powerful spell/ability is. This game it actually matters, noticeably. And yea, Gwent is pretty fun, I've been running around Velen challenging everyone I can find.
Also, I kind of wish I could just play as Ciri. Dashing around like a madman in combat is ridiculously fun.