I've had Pokemon Sapphire for quite a while now. And although I've never..

I don't think you can duplicate Pokemon without cheatcodes, and even then you might not beable to. I don't use cheats, so I wouldn't know. I battle the Elite Four to train pokemon.

1. No clue.

2. Yes there is.
2a. You can use rare candies.
2b. You check a pokemon into the day care. Then you walk up to one of those things that only a mach bike can go up. Well try to go up it when not on the bike. That counts as 1 step. now tape the +pad into the up position and let it be.(You should do this with a SP while plugged into the wall ora GBA with a wall charger pack)

1:Only with cheating code devices..............
2:With AR you can get 99 rare candies or use the max stats code.

1.No, there is no way to duplicate pokémon and or items in Pokémon Sapphire or Ruby

2. I'm sorry but there is no special way to lvl up your pokémon.

Footnote from Crossy: As to the second question, it is possible to administer Rare Candies to your Pokémon, but it is not as efficient as leveling up legitimately in that Rare Candies will not bolster stats as much. That's a common misconception in these games.

There is no duplicate code because it doesn't save when you change boxes. BUT when you deliver the devon goods to CPT. Stern in Slateport, go back to rustboro and talk to the President and he will give you an EXP. Share. It's a hold item that gives Pokemon experience even if it didn't battle.

1. No clue.

2. From what i've been reading is BAD!! rare candies only give 1/3 the original stats you were supposed to get!! battle the elite four.