Updating easyblog's categories for every post.

Hi Team,

our website is about to renew it's front-end layout, also the menu items and categories.
right now we have like a hundred posts on the website.

and i got two questions,

1. If i want to re-structure the categories(means i'll get rid of the old categories), i have to update each post one by one, or is there any way i can do it more efficient, faster?

2. when i was setting up my new menu and categories. i want to setup a couple main categories in easyblog, and these main categories will also matched with my new menu items, but every main categories will have sub-categories, and these sub-categories will be used in every post. which means i want sub-categories as primary. (attach image 01)

but the questions is, if i set this up, when i click that post, except the post content itself, the page layout will show up other modules from other pages.(attach image 02)

so the questions is, is that possible i can set my sub-categories as primary categories, and after i click the post, i will show the post content only.

Hope my description not too confuse to you.

Thanks,
Amy.