Yes, you can use the stock for prints. No need to ask. On or off DA.
Yes, you can change the stock to fit your needs. I have no problem with your creativity. I hope I just fuel it.
Link back to this site so others can find the stock.
Yes, you can post your creation using this stock on other sites.
Do not claim this stock as yours, Nor use it for brushes or tubes to put on other sites. Do not sell this stock 'as is'. You must create art using the stock.
You can make backgrounds using this stock if you like.
My art account.