Problem with Image alligment and Bullet

Hi, i’m new on wordpress.I’m working as an admin in a bengali public blogging platform,which is created on wordpress.I’m having some problem with image alignment and bullet on the post.
Image can’t be set in middle,if i set image in the middle on the posting editor it appears middle. But when it is published, it appears left. Also Bullet is visible in the post editor but it can’t be seen after the post is published.

i’m using simplista theme and the css codes are given below.Please help me get out from this.

Theme link: https://www.wpnow.com/themes/simplista