Blog Page Is Not Formatting Correctly...

Hello,

I have been working on developing my site at http://www.twitspike.com. Things are coming together relatively well, but I'm getting caught up on a few details:

1) On my blog gallery page, it seems that the Showcase template may have something quirky going on. In this theme, it should have 3 posts go across the page. If you go to this page: http://www.twitspike.com/archives/category/twitspike-blog-2 , you will see that the first row of blogs has three blogs listed. The second row from the top, only has two blogs and then an empty space where the third blog post should be. Rows 3 and 4 are the same as row two and then the final row only shows one blog post. (You can also see screenshot below.)

I have modified the length of the posts, plugins, etc. but this same problem persists. I am looking to have three blog posts featured in each row so that the page looks consistent and professional.

2) Has anyone come across a plugin/method/code modifications for making each post have the same 'featured image'. As you can see on my page (link above), I'm just using the same image for each blog post, but updating each blog manually (for 300-400 blog posts) is going to be tedious and time-consuming.

Thanks for your time and help.
YoungMoney