I personally would never fault someone for simply not knowing or understanding something. If you really did read through the forums and you have questions, we're not gonna burn you at the stake.
First of all, my generator program is not 100% complete. For the purposes of generating a common Pokémon that you can encounter in DPPt, it should be fine; however, no matter what you do to create a Pokémon, you should check it against Sabresite's Legality Checker program.
Beyond that, you don't need anything other than your preferred generator tool.
Any Pokémon that is legal for DPPt will also be legal in HGSS, of course.
As I said before, as long as you check your PKM files with Sabresite's Legality Checker, you need nothing else.
No prerequisites are "necessary", but bear in mind that unforseen consequences will always be possible when you break the game's sequence. Plus, we don't have a perfect map of the DS save files, so there's no telling what as of yet uknown values might or might not be generated / important throughout the game's progression.