Hello everyone who replied to me. Thanks for every tip. Yesterday I did the described route from Kokrško sedlo to Skuta and back over Dolgi hrbet to Češka koča. I had a self-belay kit and used it on Dolgi hrbet 2x for a better feeling. For the rest, as you write, you don't need it. The tour is demanding physically, especially, but if you are concentrated, there is no problem. The tour is very very nice, scenic, and I recommend it to all mountain lovers. A helmet is essential!