1. Partner is not needed for development. CSP can access an environment if they are a delegated administrator
2. A trial subscription can be used which can be extended beyond the initial 90 days. You can also create an environment as a partner with cdx demos - cdx.transform.microsoft.com/
3. No. Vscode is the development tool of choice and it is free
4. Implementation costs if you have a partner involved would include things like: consultancy to design a solution, project mgt., developer costs, testing, documentation, training, UAT support, data migration, post go live support
5. I believe it is available now, in a form: docs.microsoft.com/.../countryregional-expansion--saudi-arabia
