Cynthia doesn't appear in SoulSilver. The Champion you verse is Lance. He has 3 Dragonites, a Charizard, an Aerodactyl, and a Gyarados.
use the pokegear
You don't you have to use an Hm on a Pokemon
Yes
latious
eevee
you get heracross or combees when you headbutt a tree
yes you can , ok
You can use a thunderstone on pikachu
you can't, but in kanto you can use the radio
Ecruteak
use a thunder stone on eevee
I advise you to use your map.