Editing or Upgrade wordpress multisite project

Hello Every one I have a website. it is already working with wordpesss multisite and with multidomain. My website is about complete business solutions. My website is working well but I need more proffesional view and more easy control for my user. I have 5 section in my website I am using 3 type theme and many type plugin from Envato market Some Theme And Plugin using in my site: I am using "Point finder" theme for my website Secondhands and crewfinder section Also I am using "Wp Rental" theme for my Booking section. This section is working as [login to view URL] And I am using Woocommerce and "Rehub"theme with Marketplace extension in my marketplace section. Also I am using "Multisite User Management" and Userpro Extention for Sencronize user each section and for one login system. Vs. All themes and plugins have diffirent control panel. This is caused the problem. - I need Just one user Control Panel for all sections. - I need More secure website - I need more faster website - I need just one view for all section. I don't Want to give my website detail here. Please contact me if you intresting. I will give you detail and my website link. And than I will tell you what I need. and you will understend my business model .. Maybe You can change my base script wordpress to another one. Maybe you can creat my business model with Symfony or laravel, Or maybe just You can write new user control panel or new theme for wordpress. I need your Advices