Guild Wars 2

So basically I have a good computer that has to run the game well,but the problem is that when I play i randomly see some textures and hollow objects pop out. Like trees in sea and some walls or rocks in the air or something.What should i do?

I think that crafting would be a lot easyer if there would be more trees that could be chopped and more ores that could be mined.When i play as asura i find very few of them.And that makes some kinds of crafting pretty difficult.

So i have Acer Aspire 5750ZG and it should run game well,but every time I enter
game it’s start lagging and graphics are weird because all kinds of props randomly spawn
and than dissapear,pictures are sometimes blinking and some strange green,gray,yellow
and purple lines are flying in game.I thought i had old video card drivers,but after
updating nothing changed.Programs and websites that scan your computer and
compare them to game requirements say that i douldn’t have problems running the game.
Could you plz help me?