Newly created application contains this error:
"Dynamic Web Module 3.0 requires Java 1.6 or newer." and no facets are selected (except JBoss Maven Integration)

After adding

<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.0.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>

to pom.xml and updating maven project configuration, dynamic web module and other facets were ok.

Maybe you can add this to OpensShift Maven profile.