Update WP site and fix issues

I've recently taken over this WP 4.6.3 site ([login to view URL]) from previous webmaster. I've lost touch with developer who made this site and with previous webmaster. This site is child theme of "the7" parent by Themeforest. I never received Themeforest secret API key from original developer. I had problems with Visual Composer because it was old version but couldn't update it because it was integrated into theme. So I bought new version of VC with licence and it was installed stand-alone. Updating VC caused problems with Testimonials (unable to display Testimonials in slider mode) and caused problem with Blog (unable to display correct number of posts on page and problem of duplicate posts). Now I purchased new version of "the7" from Themeforest. You need to: 1. Create a staging copy of my site on my server (Siteground) for testing purposes 2. Update Parent theme ("the7") - you'll need to generate API key first at [login to view URL] 3. Update all plug-ins 4. Update Wordpress to latest version 5. Do full testing for any issues 6. If necessary install a new blog engine 7. Migrate from staging environment to live 8. Do full testing for any issues (including Testimonials, Blog and VC) First milestone released at #5 and final milestone released at project completion. At the end of the project WP and all plug-ins should be updated and functioning correctly. Issues with VC, Testimonial and Blog will be fixed. Of course, you take backups at all stages to avoid disasters. Also website should have zero downtime.