1. how did yakko,wakko,and dots mom and dad die? 2.did there parents die? 3.were they really poor at the beginning 或者 something then they 移动 to the W.B. tower? i'm kinda confused

It never actualey says how, but I'm sure they died because of natural causes.
Yes, there parents did pass away
they were drawn into this world and when they ran out of cartoon Ideas ol' plotzy locked them up in the tower.

i think the parents of yakko,wakko and dot are still alive and someday would be reunited with their children

King Savar killed their parents