Are prayers interfering with Divine will? Make prayers that are true to yourself. If what you really want is money, but you are praying to be spiritual, then you have a lack of focus. Guru tells us to just pray for the gift of the Naam. But Guru also tells us we can ask for whatever we need, and it will be granted.
Is praying for worldly things wrong? Some people really feel guilty about praying for things. If you feel guilty about it, then let it go… or get rid of the guilt. Either way works. Why would you feel guilty about making a request? If I ask for prashad I don’t feel guilty. If I ask for a roti in Langar I don’t feel guilty. So why feel guilty if you are asking for help in your life?