As you haven't given a secific glitch and I can't write all of them out I will just leave a link to a good webpage: http://www.cheatsguru.com/nds/pokemon_pearl/hints/glitch/#id808664
Yes.
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.
unless you have action replay then i doupt there is cheats but on the bright side there would be glitches
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.
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.
Google Pokemon diamon glitches sorry im not much help
you can find great glitches on IGN.com
there is no actual glitches like Pokemon yellow but there are certain cool hidden things throughout the game
All of the pokemon games have glitches in. Although you will notice that the older the games get the higher the amount of glitches there will be.
Yes.
Yes.