No, you can't set pokemon back a level unless, you're emulating and saved before it leveled up
you use pal park to get emerald Pokemon to pearl bur you can't transfer them back to emerald
no
you should have to level 70+S then some level 50+ as back ups and for healing use the cheap herbs that can be bought at lavender town
Dialga is not in that Pokemon Emerald. Back when that game was made, Dialga didn't exist.
No.Once you saved another place on Pokemon Emerald , you cant go back to where you saved last time
i am sorry to tell you that you can't you can't you have to trade them to emerald clone them in emerald and then trade them back
You can't get Arcues on Emerald. It didn't exist back then.
It is impossible to transfer back Pokemon you migrated from emerald, ruby, sapphire, fire red, leaf green etc... to Pokemon diamond/pearl.
trade them and then trade them back
you can't get another one if you gave the TM dig to the pokemon. but sandshrew learns dig at a certain level. *I assume you have Sapphire, Ruby, or Emerald*
After defeating the Elite 4, go back to Mosedeep City and go into Steven's house. There will be a Pokeball on his table containing the Pokemon Beldum. Beldum evolves into a Metang at level 20.
Pokemon Ruby Sapphire and Emerald. hope this helped!