Enhance Shopify Site with Key Functionalities

I have Recently got a shopify Website Done the Person who did it missed out on some key functionalities , the website is a B2 B website for a single Corporate its sole purpose is to facilitate its employees to be able to order Printed stationary from the website , As of now a catalog and listing is already done its missing on the following
1) the website should authenticate a specific company domain name via email OTP verification or any other similar process before letting a person inside the website
2) A check out form needs to be filled by the person which has key details along with address and phone number verification
3) We need to Feed the address book with branch Code address and pin code Number so that person while filling the check out form can choose desired address from the drop down list and excel will be shared for the same it needs to be uploaded or integrated in the website
4) Once the order is Placed a mail needs to be sent out to the person immediate senior whose mail id will be in the check out form again domain verified
5) The senior will recieve a mail with 2 Buttons saying order approved or rejected Incase the order is rejected it goes back to the orginal person who initiated the order
6) Incase the order is approved a mail confirmation is sent to 6 to 7 email Ids with complete order summary dispatch address contact details etc
7) The Approval process be like when the immdiate approving boss receives the mail he could click accept or reject in the mail, taking home to website where he clicks on these buttons again and the further process gets initiated
8) besides these functionalities there could be a few more inputs from the customer as he doea pilot and validates if everything is order