Eugene, yes if your project requires too many resources you commit a war to the repository into the deployments folder.
You can do that by dragging a WTP project or actual war (right click > Mark as Deployable first) onto the OpenShift server and it will happen automatically.
If you do not need the maven build then disable it, by removing the pom.xml file or do 'touch .openshift/markers/skip_maven_build' to tell openshift you don't want the maven build executed.