Finish Wordpress Website with Custom Web Application

My project involves the finishing of a website that sells people custom postage files in order to bulk mail with US Postal Service. I have software that creates these files but the desired website will bridge the gap between the user, myself, and this software. In order to create the custom files the user will fill out a form choosing their settings. So here are my project parameters: I need a website that is centered around this form submission. Currently I am using Gravity Forms for this form. This has worked quite well but there is a few things missing from gravity forms that I need in order to make everything work for me. If you'd like you can review my form (it is not fully complete yet) at [login to view URL] 1) My form currently uses a file upload. I need a web application that once a ".csv" file has been uploaded, the file's current headers are then displayed. The application then forces the user to map the headers from a preset list of headings that matches with their own header. This is a bit confusing so I have provided an image that shows a software application that has the same desired "header-mapping" function (A free backend application that has a similar mapping function is "WP Ultimate CSV Importer Plugin." This might help with seeing code). 2) Pre-saved settings. Users need to have the ability to save the settings and recall the selections that they select in the form. Ideally, at the end submission point the user would be prompted something like "Would you like to save these settings for future Submissions? By saving your settings, any future project with similar parameters will be super fast and simple." The user would then give the form a custom name. From then on when a user, with pre-saved settings, started a new form submission they would be prompted "Create New Submission" or "AutoFill form based on _____ settings" 3) Auto export submission as a ".csv" file. Once the user has submitted their form and paid for the submission of the form, I need their uploaded file and the form submission file to be auto-exported to an FTP (It doesn't have to be an FTP but this was the most logical idea that I had). From here I will have my own programming that identifies the submission, downloads the files, runs their submission through the postal software, and emails them their custom files. An auto email that sends the two csv's would also likely work. 4) Detect number of entries and charge more. I would like the ability for the web application to detect the number of total entries (rows of data). Then have a tiered pricing, as an example 0-10000= $10 (base price) +$0; 10001-50,000 =$10+$2; 50,001-200,000= $10+$3; Maximum file size of 200,000 rows of data. Other Website needs: 1) Basic CSS work. I like the theme that I have though some changes would be helpful 2) Ecommerce. I need the following ecommerce needs. Pay by submission. Upon completing the form users would pay for the submission. Pay by subscription/credit. I would also like the option for users to by multiple submission "credits." i.e., you pay $10 for 1 submission or if you buy 10 you only pay $75. Subscription would be you pay a monthly fee and then are given a certain max amount of credits that can be redeemed per day/ per week/ or per month. I have generally used woocommerce as my ecommerce plugin and it seems to have a lot of this functionality just needs some customization. 3) Security. This site involves companies and individuals uploading pretty expensive data. Mailing/Contact lists are highly prized so every measure of security would be needed. I've noticed in my own form submission that I can download the file just by putting in the correct web address even when logged out (i.e.; [login to view URL]) This would need to be secured and only accessed by administrator and appropriate users.