Should you apply third party security fixes to Internet Explorer

In a word NO! There's a thorough explaination of the logic behind this answer on the Microsoft Security Response Centre (MSRC) blog here.

The MSRC own the responsibility of balancing the compromise between the risk of our customers being exploited through vulnerabilities versus the risk of applications breaking due to application of security updates. The team actively research attacks in conjunction with partners to keep track of the prevalence of "exploits in the wild" to determine how much testing can take place before releasing an update.

The MSRC blog is the BEST place to go to find out the nature of threats and to get an idea of when updates are likely to be released.