if I want to take a loan for several years, will the interest rate rise or is it fixed?
Most likely it will depend on the currency in which the loan is issued. Usually all credit conditions must be specified in the contract.
I wonder if there are any tricks that ordinary banks have
If no one tries to deceive anyone, then no tricks are needed. Non-bank lending has customers are clearly less than the banks, most likely they are unprofitable to try to put tricks. but customers should behave honestly too