The plugin will use Extra Field of K2 component to make content with tabs. You can also select the fields to make with tabs like below image. You can place the tabs above item text, below item text, below introtext or use item text as a tab. You can also use {extrafieldtab/} code into anywhere item text you want to place the tabs.
Sometimes K2 having some problems with the WYSIWYG editor type. We recommend use JCE editor
2. It would be wonderful if 'Display type' can be chosen in category instead of item. With a couple of hundred items it's painful to edit every item and choose the Display type. Using the 'plugin params' kinda limiting. You are limited to use same Display type throughout your website.
Yes, since the commercial version, we have provide a inherit setting of items from category.
3. Will content plugins function within tabs?
Yes, since the commercial version, we have provide that.
4. Can I override HTML Tab?
It is possible, We invite you to look at the file plugins/k2/extrafieldtab/layout/default.php for the default layout. To override it, you have to create your layout from template/YOUR_TEMPLATE/html/k2/plg_extrafieldtab/default.php