Applicability of SuPM on data authoring, storage and report creation scenar

We have a customer requirement coming up where the customer ( a coglomerate with 10 subsidiary companies ) does not want to have an SAP EHS solution but need a data / KPI report collation and reporting application. Their sustainability metrics from individual companies will be maintained in individual systems or excel sheets. The solution they want is to have a workflow for collating individual reports and then summing it up for sustainability metrics / KPIs across the organisation

Wanted to explore the applicability of SuPm for the same. I have some questions / clarifications for the same

a) Can SuPM effectively leverage data load of individual company's reports from excel sheets or portal applications

b) Before uploading the same inputs can I generate a workflow of approval

c) Can SuPM work without SAP EHS

d) IF some data need to be leveraged out of SAP ERP and SAP BW are there standard extractors for same

e) How many prebuilt multiproviders are available for Sustainability metrics/ KPIs in SuPM

Please give info on any or all of these either directly or pointing to the right documentation