Ice and Fire
You have to be in distortion world and battle Cyrus. The Pokemon that Cyrus sends out are all weak against rock type moves. He has a sneasel a crobat and a hounchkrow. Defeat him and he will give you a master ball. Follow him and he will tell you where the legendary Pokemon are
Ground type moves are effective against electricity
use one hit KO moves and full restors.
Rock type moves are super-effective against fire, bug, flying and ice type pokemon.
Water, Electric, Ice, Rock and Steel moves are super effective against Aerodactyl.
no.
eruption aquaring
no they're the same.
The best way is to use Bug type moves against Mr. Mime, Espeon and Alakazam, Fire type moves against Bronzong (Fire it's its only weakness) and Flying type moves against Gallade.
shards can be used to trade with other people. in return, they may teach your Pokemon moves. there are 3 move tutors in Pokemon platinum that will teach your Pokemon moves in exchange for shards in a specific color.
There is no certain way to win against the Pokemon league. The only thing i can say is too lvl up your Pokemon and actually use items to boost the attack of certain moves
The same as in diamond &pearl