Packages are used to push the content from one AEM instance to another AEM instance, as @scott mentioned it cannot exists on its own. However, AEM can be installed on tomcat and create a hello world website

It shouldnt be as if you see all the OOB users still has the 'emailIds' as the node names

Make sure the nodeType of the parent Node where the tab is created is compatible with the nodeType of your tab_data_sourceCan you post the XML of your component so that we can trace out

Is it for the same component or different ? can you post your updated XML with which you are trying

my-foundation/components/page/detail -  is each one of these nodes are 'nt:folder' ?

Check the XML in your 5.6 version. Ideally, primaryType is a default/mandatory property that will have when you create any node !

Can you try with this<?xml version="1.0" encoding="UTF-8"?><jcr:root xmlns:cq="http://www.day.com/jcr/cq/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0" xmlns:nt="http://www.jcp.org/jcr/nt/1.0"          jcr:primaryType="cq:Dialog"          title="Data Source"          xtype="panel">    <items jcr:primar...

If you are using AEM 6.x, make sure you have the relevant indexes created as oak doesnt index automatically

External Login Module for Oak is different and onUserSync and onGroupSync are not as part of callback. You can refer to Oak API as @scott mentioned 

Agreed, we should be putting effort on customizing only if its a 'MUST HAVE'. Else anyhow the author would know how the product works and they should be able to handle it