Hi,
You're not the first one who asked for the product creation in several steps.
But I don't like the fact that the product is created without all data, so I don't think the "several step" is a good idea unless that the product is not created during the different steps.
Because the product can have some validation to perform, if the product is uncompleted it will be difficult to do the checks correctly.
And if you have some plugins or mass-action, you won't have a complete product when the triggers will be called.
So if we have to implement such thing, it will be more a "display trick" system where all product data is passed but where the page just display a partial interface.
You can have some kind of counter (like in the checkout) and when you are in the last "step", you can display the "save" button instead of the "next" button to display the same page for the next "step".
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.