While "slow startup" only affects a few instances, the majority of these may be fixed through an environmental variable to prevent SecureRandom from waiting for entropy. Use this environmental variable to trigger the use of a less random source of entropy: -Djava.security.egd=file:/dev/./urandom. Further details can be found at the following links:

JDK-6366924

How to solve performance problem with Java SecureRandom?

To speed up red5 apps, I suggest reading through this first as it covers Tomcat apps and they are very similar and also in most cases run within our embedded Tomcat container.