The lady near the Sudowoodo (Thing that looks like a tree that shakes) owns the Flower Shop in Goldenrod City, go there and one of the workers will give you the Water pail. Hope this helps!
between goldenrod city and ecruteak city on route 36
Earthquake is TM26
Get rid of Sudowoodo
route 221
Blackthorn city
Nothing
celadon
Very simple if you beat the gym you most go (next door) to the flowershop talk to the lady she will give you a squirtle bottle use it against sudowudo en you fight (you can catch him) (hes is level 20)
Defeat the Goldenrod GYM leader Whitney and then go to the little house next to the GYM and talk to the lady and she will give you a squirtle bottle and you use that on Sudowoodo
Play the flute to it.
Blackthorn city
It is impossible to move a Pokemon from SoulSilver to Sapphire as the two games are from different generations, you can only migrate Pokemon from Sapphire to SoulSilver.