aoh
my
god
ive been losing braincells at home
is your wb working now?
im sry i miss playing wb with you

chara's grave is in the start of the game, hence the yellow flowers there
the others are in memeory of all those who died in the war

no
the yellow flowers are usually placed were someone has dusted/been buried
gaster was presumed dead when he was lost in time and space

Flowertale?