of course safe...
trading is a skill and prediction, you will quickly repay your loan if you have good trading skills, I have never heard of a bank loaner who made his loan be a capital for trading and made a huge profit, but I'm sure it's good to try if you have good trading skills.
Safe? Its never been safe because you cant be sure that you will be on profits constantly same as said above by other members of this forum that theres no sureness if you can make money because this market is always been unpredictable where you wouldnt know on when to pump or when to crash if this is the only way for you to repay debts to bank of your loan then you should think twice.
If he has good skills in trading, then it's okey to take little loan. But your friend refused your proposal, that was because he still doesn't think himself an expart trader, accident can be happened anytime. so his decision is right.let him practise more to gain more skill
Confidence on your own trading skills isnt bad but going to the point on where you do trust it up too much and taking big loans to fund your trading account then you should accept the risk behind it because once you've
failed then not only losing big amounts of money but you would also face up legal issues when you can able to repay your loan.Its better to borrow to someone (not banks or coops).