Make sure to get the modules from the store or directly from the developer. Each module has their own instructions so clients would want to check those instructions.Most v3 modules need work to work in V4Don't put instructions here for my ScriptTechs modules. Those things go in my own ScriptTechs site.
No. Wait for the client version as the developer version is not finished for using on any sites and is only for local installs. Using a developer copy will have you losing some functions that licensed clients have. Just be patient as more bugs are being fixed.
This is why webmasters make tutorials and menus. To teach users how to use things. :) You can either make your own menus for that or make tutorials for it or both.