Guild Wars 2

I can’t play at the moment, disconnected too often, long freezes; I try to do my story quest, got disconnected, and have to begin again the instance. I don’t even try to do fractal.
So I heard about WTFast. This program seems to improves my connection.
I have several question :

+ is it allowed ?
+ sometimes, I can’t login with wtfast, why ?
+ is it safe ?
+ why do I have to pay just to have a normal connection ? This service should be offered by Anet. Gw2 is the first game in many years where the connection is terrible.

I had this error perhaps 4 or 5 times in 10 min of play. I try to do my story quest, and so I have to do it each time from the beginning.
I have also a lot of freezes, sometimes 10 sec; Combats are impossible.
I see no other solution than to stop playing, if this is not corrected. I can’t do nothing.
Combats, instances, dongeons, I don’t even mention fractals.
Why is there no answers from Anet ??
Its the first game I have so big troubles. I remember playing Everquest on US servers….

npc is missing
I need this point to finish the zone

npc still missing
I miss this point to finish the zone