Does a Québec deposit institution (excluding banks) have the obligation to open an account for me?

No. Unlike the Bank Act, the Québec act regarding deposit institutions does not contain any obligation with respect to new accounts. The opening of an account in a credit union is a contractual relationship that depends on the intention of the parties in question.

What guarantees can a Québec deposit institution (excluding banks) demand before granting me a loan?

The institution granting the loan is the one that decides the conditions of the loan. It may require such guarantees as it considers necessary based on the risks attached to the loan (an investment given as security, insurance, etc.). However, it cannot require that such guarantees be acquired from it. For example, an institution may oblige you to take out disability or life insurance before granting you a loan, but it cannot force you to purchase these products from among products offered by it.

Recently, I was the victim of debit card fraud. Am I liable for the amounts withdrawn from my account by the thief?

As with any fraud, debit card fraud must be reported so an investigation can be undertaken. If the investigation does not establish any link between the fraud and the account holder and if the account holder has not been negligent (e.g.: PIN written on the back of the card), the institution will assume the consequences of the fraud, including the amounts involved.