There is no "TOMCAT_HOME" environment variable. If you set one, Tomcat won't look at it. We use that term a lot, but it's technically inaccurate, as the actual variable names are CATALINA_HOME and CATALINA_BASE. Usually, both of these variables have the same value, unless you're using a common Tomcat binary to run multiple Tomcat servers.
Bear is correct. Only JAVA_HOME needs to be set. Tomcat can determine the default values for all the other settings.
An IDE is no substitute for an Intelligent Developer.