It mostly depends on personal preference and looks. For example, if you want something that you'd like to walk barefoot on, then flagstone might be best since it isn't fine like breeze but also still has some roughness on its surface for grip. On the other hand, if you want something basic and reliable, then concrete might be your choice.
Yes, walkways can be built even in uneven ground. Different options might be better suited for different elevations, but we will advise you on our personal recommendation if you get in contact with us. If your landscape requires different retaining walls around the property, we can build steps into these to continue the pathway!
No, most of the time a walkway will not disrupt your current landscape. Depending on what you'd like us to install, we will have to move some features like rock or plants to give us space for the pathway, but we will do our hardest to clean up and put everything as it was after we're finished.