"Prepopulated items number" attribute of flexifield

I've got "Release" content type with unlimited flexifields "Tracks" inside.
Each "Track" has required textfield "Title" and optional Duration field "Duration" with default value "0:0".

There are some problems here:

1) I can't save Release without tracks because of two prepopulated tracks (with REQUIRED titles) which I can't remove in Release creation form.
2) If I remove "required" attribute from track title, release can be saved. But after each edit of Release it appends 1 additional empty track (prepopulated) and save it too. It is because of Duration CCK field contains default value "0:0" that can't be removed. So every time release is edited it appends and saves new empty track with default duration "0:0".

I guess there should be an option "Prepopulated items" with numeric value in flexifield options.
In this case I just set "Prepopulated items" to 0 for flexifield "Tracks" and it will fix these issues.

Also there should be delete buttons deleting items as was requested here: http://drupal.org/node/291864