I could use it for all sorts of things such as making money, using it as a throwing weapon, etcetera
With the teleportation I could just chain I and travel to any country while maintaining a safe speed limit for my body during transition in and out of teleporting
Free gravel has to come from somewhere, it's functionally equivalent to summoning it. (Although it could be one of those asshole genie things where they're like "I didn't say how much free gravel)
You have to go to a quarry and pick it up every time. Mind you its still free so your only overhead would be in time and transit. Just sell it below market price to landscapers.