You need a gameboy advance and a dual link
Gold chao can only be found in sonic advance for the gameboy advance. Then you put it on sonic adventure battle
Yes.
gold egg
The only way to get a gold Chao is to find (or buy) a gold Chao egg. You can find one somewhere in Sonic Adventure DX for GameCube or PC. You can, however, buy one in Sonic Advanceand Sonic Advance 2 for Game Boy.
breed a silver/gold (obtainable on sonic dx) chao and a shiny limegreen/yellow chao (limegreen is available when you have 160 emblems or more, while the shiny yellow chao is available at 80 emblems). There will be a high chance it will be invisible. Hope this helps!
You can obtain a Gold Chao in Sonic Advance 1 and 2 by finding it in The Tiny Chao Garden, in the shop. There is a chance that there will be a Gold Chao. You can get other Jewel Chao, too. You can also transfer the Chao to Sonic Adventure 2: Battle by using the GBA link cable to the Gamecube or Wii. And also you can get one in Sonic Adventure DX but I'm not sure how...I don't own the game sorry. D: But I hope that helps!
Yes they are.
eggman or there is'nt one
You need a gameboy advance and a dual link
You can purchase Gold, Silver, and assorted colored metallic eggs from the Tiny Chao garden in the GBA games. I believe it's quite difficult to obtain them in Sonic Adventure 2 Battle... it involves many ring collecting adventures, several disappointing trips to the black market, and lots of googling how to cheat a metallic chao into existence. If I were you, I think it would be worth the $5 to buy the Sonic Advance game and get your chao that way. :3
To hurt you
You have to trade one from sonic advance or sadx