I have several questions, may Allaah bless you all:
1. Is it halal in Islam to buy a product(s), have it in your house (in order to have possession of it), and then resell it to someone else with a higher price? Please note that I have not used the products and that I intend to do this as a way of business or earning money.
2. Is permission from the original company of the product or the shop which I bought the product from obliged for me in the Sharia?
3. What if the country I live in does not give the original owner of a product the right to limit what the buyer is going to do with the product?
4. What if I twist the question a bit and say that I upload pictures of the product on a website and buy the product only after getting an interested person? Please note that I do not ask the interested person for money to go and buy the product; rather, I use my own money to buy it before reselling it to the interested person. I am sorry for making my question so long. I ask Allaah to have mercy on you, O Shaykhs, and on every reader of the answer that I will get.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger. 

There is no harm in what you mentioned, and you do not need to use the product first before selling it, nor do you need to intend to use it when you buy it. It is allowed to buy the product with the intention of selling it and earning a profit. It is also allowed that you do not buy the product until you find a buyer; however, do not conclude a sale contract with the person interested in buying the product before you have it in your possession. Hakeem ibn Hizaam said, “I once asked the Prophet, sallallaahu ‘alayhi wa sallam, ‘O Messenger of Allaah, a man comes to me and wants me to sell him something that is not in my possession. So I buy it for him from the market and then sell it to him?’ He, sallallaahu ‘alayhi wa sallam, replied, ‘Do not sell what you do not possess.’” [Ahmad, Abu Daawood, An-Nasaa'i, At-Tirmithi and Ibn Maajah - At-Tirmithi graded it hasan (good)]

As for the mere promise of buying the product that the interested person needs or knowing that someone is interested in buying it or the like, it is not considered a sale transaction and there is no harm in that.

Allaah knows best.