There are a few issues encapsulated in this.
You can influence deployment order. Have a look at the conf/jboss-service.xml in the area of the URLComparator. You can substitute the default sorter with org.jboss.deployment.scanner.PrefixDeploymentSorter. There is more information in the config file on this. This would solve the problem of bootstrap deployment.
The main problem with the EARs and WARs are there are no dependency attributes.
The only way I could see an automatic hot deploy working would be if you had the servlet container SAR depend on your custom SAR. This would however force all web apps to redeploy - not necessarily desirable. I'm not sure how an EAR would respond to such an event.
However, this solution will allow you to manually change deployments and manually redeploy in the right order while solving the bootstrap situation.
Other than that, perhaps someone else might have a better understanding for a solution.