Is it possible to send bitcoins without paying a fee?
Yes, you can do that but there is a less chance that miners include you to their mined blocks, and it will takes time or even your transaction will be dropped by the network. That's why transaction fee is recommended when sending.
How many confirmations required to ensure a transaction is successful?
1 confirmation is required so a transaction will not be dropped and to avoid double spend. But some exchange requires more confirmation atleast 3-5 confirmation will do.
Is it possible to transfer without internet?
The answer is NO.
Is it possible to transfer without internet?
Yes, if you have bitcoin loaded on a physical device you can sell that device to anyone for any amount of money both parties agree upon.
I guess he is asking for the common transaction and not this way. Even there's a bitcoin on the device its too dumb if someone bought it since there are possibilities that the recovery options are still on the seller.