I think loaning Bitcoins is a great way to gain some Bitcoin while holding your investment. If you can find the right exchanges that allows lending, it can be safe as well.
Loaning bitcoins will get you poor when you don't know where you get bitcoins aswell to pay that debts i considered to earn from faucet or by referral programs while you were waiting your investments also when you hold your bitcoin there are chance that bitcoin will get high and you can earn from that. Lending is just an headache 
Yes, lending can bring a lot of trouble. Therefore, you need to look for another way to invest. I would invest in reliable HYPs. Sometimes you can find very interesting and long-term projects