Simple Yes you can have a total of 8 games per Battlenet account. Be this 8 wow accounts or 7 wow and 1 Starcraft (Though currently wow is the only available game)

You Can transfer characters between any of those wow accounts inside of the Battle net account
General Restrictions

Once a World of Warcraft account is merged into a Battle.net account, some restrictions will apply for account-to-account transfers:

• Characters may only be transferred between World of Warcraft accounts which have already been merged with a Battle.net account.

• In order to transfer characters between World of Warcraft accounts merged with different Battle.net accounts, both Battle.net accounts must be registered in the same name

You can Have more than 1 Battlenet account
Example if you have 2 Battlenet accounts this would give you the option of havening 16 Wow Accounts 8 per Battlenet account.

Now can you Transfer Characters between accounts of Battlenet 1 and Battlenet 2 the answer is yes but its a bit more tricky.

30 Day Restriction on Transfers Between Battle.net Accounts

When a World of Warcraft account is merged with a Battle.net account, an additional temporary transfer restriction is put into place. This will also affect account-to-account transfers in a few ways:

• For 30 days after the merge, character transfers are only possible between World of Warcraft accounts that are merged within the same Battle.net account.

• During the 30 day transfer restriction period, character transfers may not be made to a different Battle.net account. Transfers from different Battle.net accounts which are older than 30 days are still permitted.

• Transfers within the same Battle.net account are still subject to the standard 3-day Character Transfer cooldown.

So In Conclusion:

For the First 30 Days you can only transfer characters between the 8 wow accounts inside each Battlenet account and not between Battlenet accounts

After 30 days You can transfer Characters between wow accounts From one Battlenet account to the other. Provided they are owned by same person.

And lastly no you cannot transfer characters from a wow account into a wow account inside a Battlenet account Only Transfers from inside a battlenet account or from one Batlenet account to another are allowed

Hope This has helped explained Battlenet wow character Transfers