NA and adapt. I play on both but more lag with EUW. You just have to play slightly more cautiously and be aware of your E-disability. For example, instead of rarely taking smite wars, try to never take them, instead, opt to zone/kill the enemy JG rather than take it in the pit.
Also, confirming EUW is 100x more toxic, the moderation appears to also be 100x more lenient. Have had much more toxic players but never a ban feedback popup from EUW. NA is much more strict about certain subjects like racism for example. It's pretty rampant on the EUW server where on NA it gets hit pretty quickly.
Americans are inherently competitive, so even when someone is like "screw you, I'm throwing" on NA a lot of the time they keep trying anyway, but with more selfish plays. (like stealing own JG blue etc.). If someone says it on EUW, you better bet your ass they're throwing, and aren't even going to be low key about it.