I know the online only thing is a problem as it limits the market.
I wouldn't mind too much lag but that's only cuz I've seen what crazy things you have to kill. That and since you can already collect materials I can assume that crafting of some sort would be put in sometime.
the online only thing is because it's a MMO, it's not build for single player (single player would make you rage quit since there are no respawn areas with tones of enemies or a very strong boss) the gameplay is build on the idea that you will be playing with friends.
the type of lag it is you cant do anything, enemies dont notice you, you cant hurt them, they cant hurt you, you cant open loot containers, cant complete quests, all you can do is walk shoot and look around.
and the resource collecting is kinda a little weird, when you scrap a gun you only get gun parts sometimes (the picture of the gun parts looks like it's just some random parts nothing special) and for some reason scrapping the same armor sometimes gives you armor parts but sometimes doesn't (as in the same exact armor with, name, description, states, level, rarity) i can kinda see why they do that (dont want it to be to easy to collect resources) but it's pretty unrealistic and they could just make it where you trade in a bunch of gun parts/armor plates into a vendor to get higher level gun parts/armor plates.
for ex: you have 10 (level 1 gun parts) where you trade them to a special vendor and he gives you 1 (level 2 gun parts) and say you trade in 10 of those and you get 1 (level 3 gun parts)