You have two problems to fix here, either of which may be preventing display of that product's listing in your E-junkie Shop.
First, you need to enter your PayPal Email in Seller Admin > Edit Profile, so your Cart buttons will have a functioning checkout method available. Product listings may not display if the cart buttons we provide there won't actually allow buyers to place an order. I will reply to your related email ticket with specific details to fix your "Paypall email address already in use" problem there.
BTW, our subscription plans help you set up a recurring payment schedule in your PayPal account, instructing them to send us the same amount every month automatically. We do nothing to bill/charge your PayPal account; we just passively accept whatever payments your PayPal account sends us. This is completely unrelated to accepting checkout payments from buyers using PayPal.
Next, when you go to "List Products in your E-junkie shop and our Marketplace", then Select your product in the menu, then click "Add/Edit Listing in your E-junkie shop and our Marketplace", you need to enter some actual text in the Details field there (then click Next and then Submit to save changes). Note this Details field is not the same as the Short Description field.
Right now, you only have some E-junkie Cart button code pasted in that product's Details field, which is not necessary because Shop listings automatically include Cart buttons when you have a cart-compatible checkout method properly set up. Without any actual text in that Details field, there is nothing for us to display on that product's page in your Shop, so display of that page is disabled.