In Wordpress there care be more than one person submitting things...with plugins Wordpress can be a more CMS like than a simple blog.
Wordpress is equally vulnerable. My site was hacked by stupid 'TURKISH' hacker last month. I asked my hosting how come it so damn easy for hacker to deface my website? They didn't tell me - but from what I read somewhere in the net even pro-bloggers like Darren, Shoemoney got hacked before. My point is either you opt for Drupal, Joomla or Wordpress - none of them offer 100% hack proof system.
IMHO Drupal is the best choice for what you want to do.. I know, because my site does almost exactly what you described you wanted to do, and it's running Drupal.. Contrary to what some people say Drupal is easy to learn, and NO knowledge of PHP or other coding is necessary. They have a great forum/support site -but if there's something you cant figure out, many users here at DP (such as myself) would be more than willing to give you help/advice..