When you zone in, 100% vulnerable to attack. But for the beta, you respawn with armor and weapon if you choose. So no biggie.
There is no content, you can go outside the city you choose to start in (there is a selection of a few)... but there are really no mobs. I did leave just to check out the map and art... not bad, some nice scenic views. The main point is to stay in city and pvp in this beta it appears (which is why I can give this first impression so fast).
The combat... I need to research this more, because the mechanics are very very basic... and yes hit box matters. But if there are no skill trees to advance and make combos, it's 4 different swings and a block.
Stress test... it's black Friday... but as of right now... which is prime US gaming time...the cities I've been in had pretty low pops (and I went to the highest ones per in game chat). I encountered a max of 25 on screen. The average of about 7-10.
Game crashed 4 times, but no lag.
Will play more and report back.
Edit: Max video settings and distances on 2560x1440 resolution.