Telekenisis is the best technik, and i didnt really use them other than a select few, but it is a good idea to get them as you come across them as one of the requirements of the Sky Pirates Den is too have learnt them all so if you dont start now and try and buy most of them later in the game you usually miss the early ones in specific locations, so then you have to go on a mission all over the world to find them which is annyoing.