Opencart Customization

Hi I want to customize my opencart store. 1) Login page should appear as soon as domain name entered (example : [login to view URL] and login page should appear and (only 2 fields mobile number and enter otp fields in page) 2) change default login page (login with mobile number instead of email and instead of password use OTP) 3) change default register page ( remove password fields, condition to mobile number field minimum and max 10 digits, send sms to admin after new user registers) 4) send sms user after admin approval for that user) (approval feature is already present in opencart's latest software) 5) Should be compatible with opencart v3.0.1.x and should be compatible to any extension and themes. 6) Products, categories, cart page, checkout page, gallery etc.. any page or links should display only when user logged in. 7) Redirect users to login page if not logged in and trying to access any page by typing direct url. (for example: if user tries to access [login to view URL] by this url without login then redirect to login page). 8) login or register page should not appear if logged in by Mobile and OTP while checkout.