Yes I don't know much about them but I am sure an all shiny Pokemon cheat would work and if it does not you can soft reset until it becomes shiny but this could take thousands of tries
no
It is impossible to get a celebi in any Pokemon game without special events (such as Jeffery's Birthday at Toys R US) or with a cheating device (Action Replay, Codebreaker, Gameshark, etc. In the Japanese Version of Crystal there is a way. (POSSIBLE RUMOR IDK) Something to do with hooking something up to your gameboy. I've seen a video of it.
no but if you use a gameshark you can get it
Could be possible on GameShark
No. Its totally possible to breed unowns. you only get a bad egg if you use too many cheats at once on ar/gameshark or try and breed a legendary with another Pokemon e.g: another legendary or ditto. Just bacause a pokemons got no gender doesn't mean you cant breed it, i mean, look at ditto.
No.
It is not possible to do the masterball cheat without a Gameshark or Action Replay on Ruby although it is on Emerald.
it is not possible as legendary Pokemon are not breedable
No, it's not possible.
It is possible to find the relative location.
It's not possible, legendary Pokemon cant be bred.
without gameshark or action replay, NO