Can we have the option to "lock" items or equipment so that we can't turn it into materia or discard it by accident.

When it comes to balancing gear from different jobs it sometimes becomes an issue of trying to remember what you want to keep and what you want to get rid of since in the instance of a DOL/DOH you may use lower level gear for certain attribute boost but if you have other low level gear you may turn a piece of gear into materia that you didn't want to.