Yes.
You mean glitches. No, since the game is DS, with the wireless stuff and all, its a heck of alot harder to do that. So i dont think there are any glitches for Diamond and Pearl.
It depends on what you mean by "best."
There are no cheats without action replay for pearl but there are glitches but if some of them require for you to do the Pokemon trading thing do NOT do them because the Pokemon company can ban you from trading.Just search Pokemon pearl glitches I know there's tons of them.
yes
Any glitches the game had have been sorted by updates of the game.
You have to migrate most of the legandarys on to Pokemon pearl but there are some tricks and glitches i know off that might help. So any way some legandarys such as palkia or garintina can be caught on pearl but you need master balls to catch them normally.
no duur
Yes.
No there isn't!
unless you have action replay then i doupt there is cheats but on the bright side there would be glitches
yes
Not if you don't hack.........