I need to disable some fields based on the checkbox. If the checkbox is checked, I need to disable some fields, not hide them. When the checkbox is selected the fields need to be grayed out and not authorable.
Yes, it's totally possible, please have a look at.
Be careful, through and explain to your client that there is 0% guarantee on next AEM Release the component you are using will still work and this will increase maintenance burden on your project.
Would be perfect if Adobe did provide us a set "stable" API's to control behaviour for Granite UI elements and we did not have to mess with Jquery selectors and setters.
 How to make the textfield readonly in Touch UI
 cq5 - Conditional show / hide of fields in AEM 6 dialogs - Stack Overflow