Guild Wars 2

Hello!
I get the game and what should be my build but there are 2 questions i wanna ask you guys if you could help me with.

I got my warrior to 80 and my build goes with lot of critical damage. But i wanna be more resistant, so i need to build some health and toughness. I get that building up hp can sustain you few more hits, but if you have toughness built up than you take less damage from incoming hits, so my first question is, what is better to build for a better resistance?

My 2nd question is very similar, building ranger on power/crit. For the critical, some items give you +x% crit damage and some give you precision. My question is what is better in case you have 2 bows same level with 2% crit and 20 percision, what is the main difference between those 2?
(also: is it better to build hp or toughness on ranger?)

Tyvm for your answers

Toughness vs Vitality:
Condition damage (bleed, burning, poison) ignores your armor, which means it ignores Toughness, too.

You really can’t assess how to balacne the two without knowing the damage you’re likely to be taking.

Crit damage% and precision are similar—precision increases your chance to land a crit, while crit damage increases the strength of it. The math plays out in a similar fashion, but instead of having to consider damage that avoids mitigation, you need to evaluate on-crit effects.

In short, there is no right answer, as the answer changes depending on the situation.