Customizing Hika Shop for Guest Operations

Hi, My company seeking eCommerce solution for the Joolma and I we intended to make use of Hikashop for our backend and checkout process. Currently I am using Starter version for my POC and would purchase the business version shortly.
I see the Hikashop has already support Guest checkout, thats what we needed.
But in our checkout I intend to use product custom field to capture user's email (because our checkout flow is mostly depends on product, therefore we did not include the custom field in checkout), I just had few question and see if my requirements are feasible to be implemented.

1. Send Email notification to Guest Customer in onAfterOrderCreated and onAfterOrderUpdated, Currently I can make use of plugin to send email to a dedicated email (POC) and I think I may get the customer email from the product custom fields (e.g. $order->cart->fields->field_value) in the $order object, am I right?
2. Our shop needed to provide order tracking feature for the guest customer by input the email and order id, I know the order controller will always check if the user is logged in, therefore should we override the controller and implement our code for retrieving the order record?
3. Since we are using guest checkout, the backend is not displaying any customer information, so it is feasible for us to edit the backend views to display the product based custom value as a customer name for order? (order listing in dashboard and orders page)

I am also evaluating if it is less effort to auto creating customer record during checkout (by using the email captured from product custom field), if so can give me some ideas on where the best place to put the auto customer creation (e.g. in onBeforeOrderCreated) and also how can I save and replace the customer within $order.

thanks.

Could anyone could suggest me to overcome the problems, that would be appreciate.

Thanks Nicolas, I think I've gather what I needed