QUESTION 2 (TRADING): does that means items are no longer tradeable ?

ANSWER: Actually you can still trade items but there are restrictions. For example,

(A) you must be in the same party and game with the other persons when the item dropped.
(B) items are only tradeable among this party members only
© and this is only for a limited time only. There is a timer for when trading between these players for the item will expire.
(D) items become account bound and will no longer be tradable hence forth.