As provided in point CAMO.A.125(d)(3), a CAMO may organise the performance of limited continuing airworthiness tasks with any subcontracted undertaking, working under its Management System, which shall be included in its certificate of approval (AC-CAMO-P01-F14).
Tasks that can be outsourced include reliability control and engine health control (reliability monitoring & engine health monitoring). 

“Details of maintenance work performed” according to GM M.A.305(g) are the records that must be maintained by the person or organisation responsible for the continuing airworthiness of the aircraft in accordance with M.A.201 in order to be able to fulfil its obligations under Part M. They are only part of the records referred to in points CAO.A.090(a) or 145.A.55(a).
Maintenance organizations must keep all detailed records to demonstrate that they have worked in accordance with their respective requirements and procedures.

Yes, regardless of owner/operator approvals and scope, you have the option to sign a contract with a CAMO. The important thing is that continued airworthiness is managed by an appropriate CAMO.

Electric load analysis (ELA) is provided by the aircraft manufacturer to the operator.
These data are part of the ICAs (see AMC to Appendix H, H25.5 Instructions for continuing airworthiness applicable to point 5 of the EWIS). Changes to ICAs are changes to the type certificate that must be approved in accordance with Part 21.
Where relevant, a change or modification should contain a difference sheet for ELA, so that the operator can update the current ELA.

The standard does not impose a "basic" or "generic" maintenance program; however, Chapter 1.2 of the CAME should describe how the organisation will develop the AMP. 
The organization must define the means to demonstrate that they are competent for the management that is intended to be carried out. Certain elements, such as the IT tool to manage the AMP, access to applicable technical documentation and/or staff experience in AMP matters, can contribute to achieving this objective.

In principle, to maintain the privilege as a PRA in a CAMO Y, the experience demonstrated by performing work on a CAMO X will also be considered valid.

Yes, an organization with Part CAMO approval may have a generic scope on its approval certificate (AC-CAMO-P01-F14). However, even if the organisation approval has a generic scope, the continuing airworthiness management exposition (CAME) shall always reflect the specific scope of the organisation; It is therefore recommended that the generic scope of approval should not be excessively broad compared to the scope defined in the CAME.  
Organisations shall request from AESA any change to the scope defined in the approval certificate.

There must be an agreement between the auditor and the auditee that includes:

This applies both to remote audits carried out by the competent authority and to audits carried out by organisations on their own suppliers and subcontractors.  
Authorities/organisations that decide to use remote audits should describe the functioning of remote audits in their procedures and should consider at least the following points:

It is considered subcontracting if it manages the information, the duplication of information, or similar. It would not be subcontracting, if only the rental of equipment or space to store them were contracted, and the control and management of information was the responsibility of CAMO.