You can fetch a better rate by lending bitcoins on this forum. People get a rate as high as 3%-7% per week which is better and you can lend people with a good reputation to ensure the borrower is trustworthy.
I also buy/sell altcoins with my btc and earn a good profit. I bought ETH when the price was 0.03 and now the price reached 0.06. It's much better than lending money.
This is partially true.
If you lend to people and get a valid collateral (e.g. coins or something with a real value), then yes. Lending section will bring you more. At the cost of more time and more troubles.
If you lend to people and get account as collateral, then thing could get ugly. Like collateral account being red tagged on loan default.
Poloniex lending is one very good option and much more secure in my eyes.