How to best handle a modal with multiple tabs and buttons

We have a modal that is used for an action to Add an item and Edit an existing item. It also has a button to delete the item all together.

I am trying to determine the best way to handle the button and navigation between the tabs. Right now it is set up as:

1. You can click between the tabs to change the view
2. You can click on the x to close the modal
3. When editing (not adding) delete shows up on all the tabs
4. For the other buttons we change them depending on which tab you are on:
   • Tab 1: Delete, Cancel, Next
   • Tab 2: Delete, Back, Next
   • Tab 3: Delete, Back, Save

Some specific questions I am struggling with:

1. Is this the proper UX to handle this?
2. Should delete be on only the first only or last tab only or is it ok to have it on all tabs?
3. Should we allow navigation via the tabs too or just buttons?
4. Should the buttons change between tabs?
5. Should we save between tabs or wait until the end?

Any feedback would be very appreciated. Thanks!