BTC can be sent without a fee or with a smaller fee to what you have inclined.
how
In QT - Settings > Options > Main, change the fee amount from within there.
However it may not be possible in other wallets such as multibit.
even with large transaction byte sizes?
Well you obviously know something I don't
I have read of huge amounts being sent without a fee so I assume it's possible?
The amount of coins being sent is not important, so yes, you can send thousands of coins for free. The important quantity is indeed the transaction size and its priority, which depends on how many outputs you need to combine for the transaction, and how old those are.
Rule of thumb is that the larger the amount sent, the better (so sending 1 BTC is better for priority than sending just 0.001 BTC), and if you received / use lots of small inputs (like from a faucet) it costs you more transaction fees.
