yes. that's how i made my ralts my main starter on ss
of course you can
Yes you can.
Yes,you can trade with perl,diamond,platinum and soul silver.You can trade before beating the elite four.
You can transfer Pokemon, but you can't trade. Since HeartGold was released before Black, HeartGold doesn't know Black exists. However, Black knows HeartGold exists. You need to be on Route 16 in Black version, which requires beating the Elite Four.
Of course it can, golbat evolves into crobat if the friendship between it and u is good.
Before you beat the league, the only things you can transfer from GenIV games (inc. HG/SS) are the 13th movie Celebi and shiny beasts, using the Relocator. Only after beating the league do you get access to the PokeTransfer lab.
You can still find him on Mt. Silver, but you must defeat the Elite Four before you can re-battle him.
You cannot obtain the Azure Flute in Pokemon Diamond, Pearl, and Platinum without the use of an Action Replay.
Yes, you can trade Legendary Pokémon as well as any other Pokémon from Pokémon Platinum over to Pokémon HeartGold, you just need the regional PokéDex in both trades before you can trade.
Yes, beating the 7th Gym does not effect getting the secret potion.
Well, you can't get to the Elite four without going to SunyShore, but you MUST either capture or KO Giratina before you're allowed to go to Sunyshore.
Yes, go to any Pokemon center. You need to have passed some point in the game but this is miles before the elite 4.