I really need to be able to display the inputs for my custom fields on the itemform.php. I've ready through the forum and can't seem to find anything that works. Could you please let me know how this can be done - I would really appreciate it.

You can override the itemform.php and remove the tabs.
getk2.org/documentation/tutorials/174-templating-with-k2-and-the-concepts-of-sub-templates