How can I become the best in this game?
Practice. Practice, practice, practice is the only thing i can offer you. There are always classes to offer you tips, but practice is the MAIN thing.
What do the top 10 players know that I don't know.
This question is completely subjective and varies almost entirely with mod. There are a few universally top players who are regarded to be the best, such as Leyz and Ticux maybe.
Where can I absorb advanced information about the competitive side of this game?
I'm not quite sure what you mean by this question. If you mean competitions and events then there are frequent gmtourneys ingame with varying mods. As for forum events, just participate in as many as you can, or rather any that interest you, then eventually you'll just get better and better as you do more.
What type of training should I do to become the best?
Depends what you want to be good at. If you want to be good at taekkyon, play taekkyon.
Imo, that will give you good joint understanding in combination with aikido.
Who are the top 10 players/most known players in the competitive Toribash community?
Again, opinionated.
Many of us still play this game and win/lose without knowing what we are doing (mashing). How can we change this?
Inherantly, there's not much that
WE can do.
Uniteam server sit, and help in any way they can, regardless of ingame skill.
A lot of it will be simply practice for them, too.