it can know almost any move. if it doesn't already
Rayquaza is stronger because his moves are stronger. Giratina only has one move that is power over 100. That's Shadow Force. Rayquaza has 2 moves that are power over 100.
In Pokémon Ruby and Pokémon Sapphire, the moves Rayquaza will know upon your capture of it are Rest, ExtremeSpeed, Fly and in Pokémon Emerald, Rayquaza will know moves such as Fly, Rest, Outrage and ExtremeSpeed and in Pokémon HeartGold and SoulSilver it will know moves such as Outrage and Rest.
rayquaza is stronger because ground moves dont really affect it and water has a low accuracy
it depends on what type of attacker you want Rayquaza to be and if you want Rayquaza to be used in competitive battling. Your best choice is to check on Smogon for all of your options.
in my opinion Outrage Fire Blast Dragon pulse and fly
You can't without hacking, unless you have HeartGold and SoulSilver. Why, one word, HM Moves, Rayquaza can't migrate, you need to get Rayquaza on the Nintendo DS. (This requires HeartGold and SoulSilver. You need both, you'll see why...)
Rayquaza should not learn earthquake or ice beam. I t shoulf learn all dragon moves, like Draco meteor, outrage, dragon rush, dagon rage, dragon pulse, dragon claw, and others. If it knows all dragon moves it will be nearly unstopable, unless it meets a higher level dragon, ice, or rock Pokemon that is faster than it.
its easy just have ice type moves and smokescreen and you will beat rayquaza in no time
It depends on the moves, but have lots of reviver seeds, sleep seeds, and a link box. Link all of your attack moves together and throw a sleep seed at Rayquaza. you should then use your linked moves against him. This should end quickly with your victory if your attack stat is strong enough. I did this without using a reviver seed by simply linking the moves.
yes it is cause rayquaza wont have his brill moves if lower than level 50. it also really depends on which Pokemon u use!
Dragon and Steel Moves
Fly is an HM move - HM moves can't be forgotten by replacing it with a new one. Instead, you have to go to the move deleter to forget Fly, as is the case with all HM moves.