Guys.
All working.
I just imported my private key in a installed electrum wallet.
Bow I have a last doubt...
What should I do with the blockchain wallet? That wallet stills working?
The wallet will still work, but you can just forget about it since all of the private keys are now in electrum.
Isn't there a way to erase my wallet from blockchain?
If my wallet stiils working into blockchain.info I'm not secure because my wallet is accessible from the internet yet...
I don't think there is any way to delete the blockchain.info wallet. You can enable all of the other security settings to make it really difficult for anyone to login though. That should help, but wallet deletion is not possible.
You can archive it and delete the wallet address. I can't find proof that they delete it on the server side but it should help from client side attacks.
This method should work, i've tried it several times when creating novelty addresses (importing keys, archiving, deleting)... But like you said, you never have a 100% guarantee that blockchain didn't keep a copy, nobody was snooping on your internet traffic and your pc was 100% clean when exporting the keys...
But it's the closest you can get to deleting a key from blockchain...