Have a look at the following article 

https://pdn.pega.com/community/product-support/question/how-delegate-data-type-defined-data-explorer

https://pdn.pega.com/community/pega-product-support/question/pega-72-customising-delegated-data-table-ui

1.Can end user edit the data pages and data types?  YEs we can delegate the data types to the end user by mentioning the access group of the end user

 1. To delegate a data type, in the Actions menu of the Data Designer, click Delegate

 2. From the Delegate to access group drop-down list, select the access group to which to delegate the rule or data type.

 3. In the Title field, enter a title for the delegated rule or data type.

  4. In the Detailed Description field, enter detailed information about the delegated rule or data type. This text is displayed to the user.

Now go to manager tab and check in the configuration tab you will able to find it out

2. In the multi node system How we can run the data pages for particular nodes?(Here The data page is in node level) I think we can place the data page to node level it will available to all the users until the system restart so we can limit the access to the node by placing a when the condition to which nodes the node should have access.

3. Can end user delete the data page?

As per my knowledge, I think we can modify it but can't delete it