Re: Categories and post form
Not sure if you found a solution for this yet, but I'll give it a try...
Again, in post-form.php
Depending on how many categories you have, you could just use exclude option for the ones you don't want to show:
<?php wp_dropdown_categories('show_option_none=Select One&orderby=name&order=ASC&exclude=category 1,category 2,category 3, &hide_empty=0&hierarchical=1'); ?>
Category 1 in this case would just be the number 1 and so on.
Although, if you have a large amount of categories, then you probably just want to use the include option, so that you don't have to exclude 1,000 categories.
<?php wp_dropdown_categories('show_count=0&hide_empty=0& orderby=name&order=asc include=category 1, category 2, category 3,&number=0&hierarchical=1'); ?>
I think you'd want to go with the latter. I'm pretty tired, but it looks right to me. Let me know if you have any questions or it doesn't work for you.