2 boys using same Xbox Live account , wanting to get new xbox and live account but keep all...

Using the same account is sharing an account. It doesn't matter if they're playing at the same time or not.

They use the same account but play at different times on the same console so no code of conduct is being broken . But thanks for your reply.

Nothing can be transferred between accounts. So if you create a new account for him he will have to start all over.

Even though it's a pain for one of them to start over, I would suggest creating a separate account as that will be better in the long run. Once they get older and want to do things separately, they'll already be set up for that with less to lose. Per the
code of conduct, you're also not supposed to share accounts either.

I created an XBOX live subscription on the PC, with my email.

Now i want to sign into XBOX live on my XBOX profile, using same EMAIL.

I don't want a new profile, i want to keep using my old one.

With this account's email/password for XBL.

yep keep it on a memory card or usb drive and you can connect the profile to live

if you want the xbox account to be connected via 2 consoles at the same time

no it doesn't work that way (stolen accounts would be hard to detect if it was )

a xbox profile can be signed on live in 1 console at a time

you will have to get a family account allowing 4 gamertags if you want multiple consoles at the same time