Keyed different will provide you confidence knowing that if ever you lose one key, you will not lose control over all of your other locks in your property. While keyed different locks are more secure, they are also a heavier load. The reason for this is that you have to handle multiple keys depending on how many locks you have on your house or office. 

Keying your locks alike can save you energy and time. The reason for this is that you do not have to look for which key fits which like since they will all be the same. However, they are not secure enough for exterior applications.

The answer greatly depends on the current situation of the lock. It is true that you are dealing with severely diminished security on the most likely part of a structure to be targeted by a burglar. The ideal thing to do is to contact a professional locksmith. They will check the condition of the lock to know if it still can be fixed or if it is time for a replacement.

The answer also depends on the lock. There are particular manufacturers of locks that do not allow rekeying. However, today, almost every lock can be rekeyed. You have to make sure you contact a professional locksmith to do the job properly if you want to rekey a lock.

To make things easy for you, it is best to change your locks. This is particularly true if you’re certain that your keys are stolen and it is a master key. If this is the case, the burglar will definitely come back to your house and open every single lock in your property. However, if you don’t have the budget, you can simply have your locks rekeyed. Contact a professional locksmith to make sure you know what option is best for you.