In Custom Properties when you need to change order och delete a lot of fields it's not that easy to do this one by one.
*If there was a mode to "drag n drop" for changing the order in the fields that would be nice, now you need to "Move field up" a lot of times, to get it to the top (If I have 10-15 fields it's time consuming).
**Also, when I need to delete a lot of fields it would be nice to have a tickbox for which fields should be deleted, then "delete all" (button) would be very nice.
to quickly re-arrange the order of fields, you can use the keyboard. You can navigate through the fields using the TAB (forward) and SHIFT TAB (backwards). Use CTRL + Page Up and CTRL + Page Down to move the field up and down one position.
I will put the bulk-delete feature request on my todo list.