treat bitcoin as a normal currency that everyone use
if you ask for a loan, make sure you repay it
small loans may need no collateral and can be given to you by trust alone but big or huge loan may need collateral just in case you failed to pay on time there is something to compensate the loss of BTC of the company or the person who give you loan
for huge loans like cars and houses, if ever BTC arrived to that level where its accepted and used by the bank i dont think the BTC will be deposited to your BTC wallet but instead will be transferred to BTC wallet of the seller car or a house itself that is if BTC will be used. For schools, i've heard of a few universities in our country who accepts BTC as a form of payment but that is still something that I need to confirm.
Good idea!
I want to add one! The borrowers could sign a smart contract, agree to allocate some money from his monthly salary (bitcoin) being sent to the lenders. It involves three parties, including borrowers, lenders, your employers. Once the contracts are signed, no one can change it, except the three parties together.