CSV import and update posts for Wordpress

I want to import and update products from a CSV file to Wordpress 1. In plugin settings page, I want to see 3 dropdowns, only first time when I use this plugin, at first to see what custom post I want to use for import and update (custom post type or build-in posts, only one of them). at second, what taxonomy is used for Shop (details on 2.) and last one, what taxonomy or category is used as category tree for products (details on 3.k.) 2. On same settings page, I want to see a list with all taxonomy terms for taxonomy that I chose on 1 (Shop), even if they are empty, with no products. Each of them will show me how many products they have, date of the last import or update (date and how many days ago), a browse button with submit button where I can import the CSV files. They can be sorted by shop_name, number of products and date 3. CSV file if like attached one, first row is for headers. CSV file contain these columns that will be imported: a. product_name - this will be imported as post title b. product_description - this will be imported as post body c. tax_shop - this will be imported as taxonomy shop term (that I chose on 1.) c. tax_brand - this will be imported as taxonomy brand term e. met_product_low_price - this will be imported in custom meta product_low_price f. met_product_full_price - this will be imported in custom meta product_full_price g. met_product_discount - this will be imported in custom meta product_discount h. met_product_url - this will be imported in custom meta product_url. This URL will be scanned to avoid broken links i. met_product_aff_link - this will be imported in custom meta product_aff_link j. product_image - this will be imported in custom meta product_image and image from this link will be uploaded on server and attached to the post as featured image. Before uploading, images will be resized to 350x350 no crop image, then uploaded. I don't need full images on server! k. category - this is category tree of products, can be 5 level deep. They will be in CSV like that: Shoes/Women Shoes/Sport shoes. In this case will be imported in Sport shoes taxonomy, only if this have as parent the first two 4. product_name, met_product_url, met_product_aff_link ,product_image, category and tax_shop are mandatory, if they don't exist as headers, the CSV is invalid. tax_brand term will be created with the value from CSV, if the field already exist, then don't create again, just associate with term. tax_shop term will not create automatically, they will be created manually by administrator. met_product_low_price, met_product_full_price and met_product_discount will be checked if the are numbers (1.000,99) 5. After I start an import or update the page will be refreshed and I want to see a progress bar. Each error of importing single products from CSV file will be listed in real time. (The URL is invalid, The product image link is invalid. Tax-Shop "ZARA" don't exist. Category "example" don't exist. met_product_low_price "example" is not valid number.) 6. Update products is like that. Once already I imported some products on any shop, the next imports for that shop are updates. They will work like that: products from the new CSV file will be scanned by product_url meta to see if they are already exist from the previous updates. All products that already exist will remain intact. If some products are already imported from the previous updates and they are not in the new CSV, they will be deleted with their images associated to them, all sizes. All new products from the CSV file, will be imported. So, the process is in this order: scan products, delete old products, add new products, each process will have own progress bar, with errors and messages ( scanned 349 products, deleted 115 products, added 210 products) 7. Number of posts added per cycle must be chose to avoid the "max_execution_time" error and get more SPEED. If the processes are lowest I will cancel the project.